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INJURIES  OF  NERVES 

AND 

THEIR   TREATMENT 


BY 


JAMES  SHERREN,  F.R.C.S.Eng. 

ASSISTANT    SURGEON    TO    THE    LONDON    HOSPITAL  ;    SURGEON   TO   THE 

POPLAR   HOSPITAL    FOR   ACCIDENTS;    LATE    ERASMUS    WILSON 

LECTURER,    ROYAL    COLLEGE   OF    SURGEONS 


NEW  YOEK 

WILLIAM  WOOD  AND  COMPANY 

MDCCCCVIII 


/G  -^1 


PRINTED    IN    LONDON,   ENGLAND 


TO 


HENRY  HEAD,  M.D.,  F.R.S. 

IN  APPRECIATION  OP  VALUED  HELP,  THIS  BOOK  IS 
DEDICATED 


PREFACE 

^HIS  manual  is  intended  as  a  guide  to  the  exami- 
nation and  treatment  of  cases  of  nerve  injury. 
While   includino'  all  that  the  author  believes  to  be 

o 

essential  to  this^  it  does  not  claim  to  be  an  exhaustive 
account  of  the  subject. 

A  large  proportion  of  the  material  used  has 
appeared  in  papers  published  in  ''  Brain '  (with  Dr. 
Head)^  in  the  'British  Medical  Journal/  'Clinical 
Journal/  and  '  Lancet.^  The  illustrations  are^  with 
three  exceptions^  original.  Of  these  three^  two  are 
modified  from  illustrations  given  by  Gushing^  one  from 
a  diagram  in  a  paper  by  Morriston  Davies.  The 
photographs  have  been  taken  by  Mr.  Wilson^  photo- 
grapher at  the  London  Hospital_,  to  whom  my  thanks 
are  due. 

JAMES    SHERREN. 

Devonshire  Street,  W. 
February,  1908 


CONTENTS 


CHAPTER  PAGE 

I.  Classification  and  Method  of  Produc- 
tion OF  Nerve  Injuries       ...  1 

II.  Symptoms     resulting     from     Complete 

Division  of  a  Peripheral  Nerve       .  15 

III.  Symptoms    resulting   from    Incomplete 

Division  of  a  Nerve    ....  35 

IV.  Method     of     Examination     of     Nerve 

Injuries          ......  45 

V.  Differential  Diagnosis  ....  61 

VI.  Treatment  of  Nerve  Injuries         .         .  72 

VII.  Plastic  Operations  upon  Nerves   .         .  85 
VIII.  Method    of   Recovery   after  Complete 

Division  of  a  Nerve  and  Suture      .  99 
IX.  Method  of  Recovery  after  Incomplete 

Division  of  a  Nerve   ....  123 

X.  Pain  Complicating  Nerve  Injuries        .  132 

XI.  Cranial  Nerves         .....  150 
XII.  Nerves    of    the    Cervical    Plexus    and 

the  Cervical  Sympathetic  .         .         .178 

XIII.  The  Brachial  Plexus       ....  183 

XIV.  Nerves  Supplying  the  Muscles  of  the 

Shoulder  Girdle  .         .         .         .211 

XV.  Diagnosis  of  Lesions  of  the  Brachial 

Plexus 219 

XVI.  Nerves  of  the  Upper  Limb     .         .         .  230 

XVII.  The  Cauda  Equina 276 

XVIII.  Nerves  of  the  Lower  Limb    .         .         .  287 

Index 305 


INJURIES  OF  NERVES  AND 
THEIR  TREATMENT 

CHAPTER    I 


Classification  of  Nerve  Injuries — Method  of  ProcUictiou  of  Nerve 
Injuries :  (1)  by  Penetrating  Wounds,  Accidental  or  Oj)era- 
tive ;  (2)  by  Pressure ;  (3)  by  Traction — Nerve  Injuries 
complicating  (a)  Fractiu-es ;  (b)  Dislocations;  (c)  Sui-gical 
Procedures — Gunshot  Injuries  of  Nerves. 


Injury  to  one  of  the  principal  nerves  of  a  limb 
is  an  accident  of  extreme  gravity.  Its  recognition^ 
exact  diagnosis  and  correct  treatment  is  of  tlie 
utmost  importance.  Under  tlie  most  favourable 
circumstances  a  period  of  incapacity  results  which 
often  extends  into  months  and  may  necessitate 
entire  change  of  employment. 

It  is  necessary  to  be  acquainted  with  the  prognosis 
of  the  various  forms  of  injury  to  Avhich  each  nerve  is 
liable  ;  such  injury  often  affects  the  future  career 
of  the  patient^  and    in  many  cases  the  interests  of 

1 


2  INJURIES    OF    NERVES 

employers  or  their  representatives  are  also  involved. 
It  may  fall  to  tlie  lot  of  any  medical  man  to  be 
called  npon  to  statC;  for  example^  the  probability  of 
a  patient  after  primary  snture  of  one  of  the  nerves 
of  the  hand^  being  able  to  again  follow  employment 
requiring  manual  dexterity,  and  at  what  date. 

The  subject  will  be  dealt  with  from   the  clinical 
standpoint  with  these  questions  in  view. 

Classification  of  nerve  injuries. — All  nerve  injuries 
fall  into  one  of  two  groups  :  (a)  Those  in  which 
the  symptoms  indicate  complete  interruption  of 
continuity;  (b)  those  in  which  the  symptoms  point 
to  incomplete  interruption  of  continuity.  For  these 
two  groups  I  employ  the  terms  (a)  "  complete '' 
and  (6)  ''  incomplete  '  division/  ^^  the  word  "  divi- 
sion ''  being  used  in  connexion  with  the  conducting 
portion  of  the  nerve.  This  avoids  terms  such 
as  ''  concussion/^  "  contusion/^  "  laceration/^  Avhich 
are  of  use  in  describing  the  method  by  w^iich  a 
nerve  is  injured  but  do  not  form  the  basis  of  a 
useful  classification ;  they  omit  the  one  fact  of 
importance  in  treatment  and  prognosis,  whether  the 
separation  from  the  central  nervous  system  of  the 
structures  supplied  by  the  injured  nerve  is  complete 
or  incomplete. 

But  it  must  be  remembered  that  interruption  of 
conduction,  permanent  or  transitory,  complete  or 
incomplete,  may  result  from  an  injury  which  leaves  the 
naked-eye    continuity  of  the  nerve  intact.    For  this 


CLASSIFICATION  3 

type  of  injury  I  use  the  term  "  physiological "  ;  when 
the  injury  results  in  anatomical  solution  of  continuity^ 
"anatomical^'  division.  Hence  the  complete  classi- 
fication is  into — 

[Anatomical. 

Complete  division        { ,^,      .  ,      .     . 
^  ll'hysiologicai. 

[Anatomical. 

Incomplete  division    1,^1      -  ^      •     ^ 
^  LPhysiological. 

There  is  no  sign  apart  from  inspection  of  the 
nerve  by  which  it  is  possible  to  tell  into  which  of 
the  subdivisions  (anatomical  or  physiological)  the 
injury  falls.  The  second  part  of  the  classification 
must  therefore  often  be  omitted^  or  added  after 
operation. 

Methods  of  production  of  nerve  injuries. — All  nerve 
injuries  may  be  referred  to  one  of  three  causes  :  (1) 
Wounds^  accidental  or  operative;  (2)  pressure;  (3) 
traction.  These  affect  the  individual  nerves  in 
varying  frequency.  For  example^  the  median  and 
ulnar  are  most  often  injured  by  penetrating  Avounds, 
the  musculo-spiral  as  the  result  of  pressure,  the 
brachial  plexus  as  the  result  of  traction. 

Wounds  of  nerves,  accidental  and  Operative. — 
Accidental  wounds  in  the  region  of  the  wrist  and 
lower  third  of  the  forearm  are  responsible  for  a  large 
proportion  of  the  nerve  injuries  of  civil  life.  They 
are  often  complicated  by  division  of  tendons  and 
form  one  of  the  most  serious  accidents  w^e  are  called 
upon    to    treat.      In    the    lengthy  operation   for   the 


4  INJURIES    OF    NERYES 

union  of  the  divided  tendons  the  nerve  injury  is  not 
infrequently  overlooked. 

Sometimes  the  nerve  is  divided  through  a  small 
punctured  wound,  and  for  this  reason  nerve  injury  is 
not  suspected. 

The  nerves  which  most  often  suffer  in  this  way 
are  the  median  and  ulnar,  alone  or  together,  and  the 
radial. 

It  is  impossible  to  avoid  the  division  of  many 
small  cutaneous  nerve-branches  during^  the  course  of 
a  surgical  operation.  Such  injuries  are,  as  a  rule, 
of  little  importance  ;  regeneration  and  restoration  of 
function  follow  if  the  edges  of  the  wound  are  brought 
into  accurate  contact  and  the  wound  heal  by  first 
intention.  In  some  cases  larger  branches  are  divided, 
of  necessity  or  accidentally,  and  the  symptoms  persist. 

The  nerves  most  often  injured  during  the  course 
of  surgical  operations  are  the  branches  of  the  cervical 
plexus  and  the  spinal  accessory  in  operations  upon 
the  neck,  and  the  facial  nerve.  In  ojoerations  ujDon 
the  neck  the  spinal  accessory  should  be  carefully 
avoided,  or  if  divided,  sutured.  Its  section  produces 
a  noticeable  deformity  of  the  shoulder  {vide  p.  175), 
which  is  more  marked  if,  as  usually  happens,  the 
branches  given  to  the  trapezius  from  the  third  and 
fourth  cervical  are  divided  at  the  same  time. 
Injuries  of  the  sensory  branches  of  the  cervical 
plexus  may  cause  pain  and  tenderness  in  their  area 
of   distribution.      The   trunk  of  the    facial   nerve  is 


METHOD    OF    PRODUCTIOX  5 

most  often  injured  in  operations  upon  the  mastoid 
and  middle  ear^  its  branches^  in  operations  in  the 
parotid  and  submaxillary  regions. 

Next  in  frequency  the  nerves  of  the  abdominal 
wall  suffer.  Incisions  in  the  linea  semilunaris  must 
of  necessity  divide  the  lower  dorsal  nerves  supplying 
the  rectus  abdominis^  and  may  aid  the  formation  of 
post-operative  ventral  hernia.  Fortunately  it  is 
rarely  imperative  to  open  the  abdomen  through  an 
incision  in  this  situation.  In  most  operations  in 
the  upper  abdomen  the  incision  should  be  made 
through  the  posterior  sheath  of  the  rectus^  after 
pulling  the  muscle  outwards.  If  this  is  inadvisable, 
as  in  the  operation  of  cholecystostomy^  the  fibres  of 
the  rectus  should  be  separated. 

The  last  dorsal,  ilio-hypogastric  and  ilio-inguinal 
nerves,  particularly  the  former,  are  exposed  to  injury 
in  their  course  behind  the  kidney.  This  injury  may 
be  avoided  by  making  all  incisions  parallel  to  their 
course  and  remembering  their  position  when  it  is 
necessary  to  enlarge  the  wound.  The  last  dorsal 
nerve  is  occasionally  included  in  a  ligature  with  the 
first  lumbar  artery.  Severe  symptoms  may  be  pro- 
duced by  injury  to  any  of  these  nerves  {vide  p.  144). 

The  ilio-iuguinal  nerve,  as  it  lies  beneath  the 
structures  forming  the  spermatic  cord  and  passes  out 
at  the  external  abdominal  ring,  is  sometimes  cut  into 
or  included  in  a  ligature  during  operations  upon 
inguinal    hernise.       This    nerve    should    be    always 


6  INJUEIES    OF    XEEYES 

recognised  and  carefully  preserved.  Considerable 
inconvenience  may  result  from  its  injur}^ ;  I  have 
knoAvn  the  pain  severe  enough  to  render  operation 
necessary. 

In  all  operations^  hoAvever  simple^  the  course  of 
the  neighbouring  nerves  should  be  borne  in  mind. 

Pressure  on  nerves. — The  pressure  may  be  momen- 
tary or  long  continued^  the  result^  for  example^  of  a 
blow  or  involvement  in  callus.  As  an  example  of 
the  former^  a  blow  on  the  ulnar  nerve  behind  the 
internal  condyle  of  the  humerus  leading  to  a  tem- 
porary interference  with  the  functions  of  the  nerve 
may  be  cited.  Of  the  latter^  involvement  of  the 
musculo-spiral  nerve  in  the  callus  repairing  a  fracture 
at  the  junction  of  the  middle  and  lower  thirds  of  the 
humerus. 

The  musculo-spiral  nerve  suffers  most  often  from 
this  tj^pe  of  injury.  It  may  be  pressed  upon  during 
sleep,  or  by  crutches,  iuA'-olved  in  fibrous  tissue  or 
callus,  or  compressed  by  a  displaced  fragment  of 
bone.  Less  often  the  brachial  plexus  is  compressed 
by  the  dislocated  head  of  the  humerus,  the  external 
popliteal  by  the  violence  producing  a  fracture  of  the 
neck  of  the  fibula  or  other  direct  pressure.  The 
median  and  ulnar  nerves  may  be  injured  by  tight 
splints  or  bandages.  In  Yolkmann's  ischaemic  con- 
tracture of  the  forearm  muscles,  when,  as  is  usually 
the  case,  it  results  from  splint  pressure,  involvement 
of    these  nerves  is  rarely  absent.      The  pressure  of 


COMPLICATING    FEACTUEES  7 

the  strapping  used  in  putting  up  a  fracture  of  the 
clavicle  by  Sayre^s  method  is  responsible  for  some 
cases  of  injury  to  the  ulnar  nerve  leading  to  a  tem- 
porary loss  of  conduction. 

Traction  injuries. — Injuries  due  to  overstretching — 
traction — aifect  chiefly  the  brachial  plexus.  They 
form  an  extremely  important  group  to  which  atten- 
tion has  recently  again  been  directed.  Brachial 
birth  paralyses  and  injuries  of  the  plexus  due  to  a 
fall  upon  the  shoulder  or  violence  applied  to  the 
side  of  the  head  owe  their  origin  to  this  cause  {vide 
p.  187).  The  great  sciatic  nerve  or  its  external 
popliteal  division  are  sometimes  injured  during  the 
manipulations  necessary  to  the  treatment  of  a  con- 
genital dislocation  of  the  hip^  or  the  reduction  of  a 
traumatic  dislocation. 

The  overstretching  may  result  in  anatomical  or 
physiological  division,  which  may  be  complete  or 
incomplete.  Physiological  is  more  common  than 
anatomical  and  incomplete  than  complete  division. 

Nerve  injuries  complicating  fractures. — The  nerve 
may  be  injured  at  the  moment  of  the  fracture — ^v'l- 
mary ;  involved  in  the  process  of  repair,  or  pressed 
upon  by  the  displaced  end  of  the  bone — secondary. 

The  primary  injuries  fall  into  two  groups,  (ft)  in 
which  the  nerve  injury  is  caused  by  the  fracture, 
for  example,  injury  of  the  musculo-spiral  from 
bruising  or  laceration  by  the  fragments  of  the 
fractured    humerus ;    (/>)    in   whicli    the    nerve  injury 


8  INJUEIES    OF    NERVES 

results  from  the  violence  producing  tlie  fracture,  a 
fall  on  the  point  of  the  shoulder  causing  a  fracture 
of  the  clavicle  and  a  traction  injury  to  the  brachial 
plexus,  or  direct  violence  applied  to  the  outer  side 
of  the  leg",  a  fracture  of  the  neck  of  the  fibula  and 
an  injury  to  the  external  popliteal  nerve. 

The  nerve  may  be  ruptured,  contused,  lacerated, 
or  compressed  between  the  ends  of  the  bone.  In 
most  cases  the  symptoms  result  from  pressure  and 
cause  weakness  or  paral3^sis  of  muscles  accompanied 
by  a  loss  of  sensibility  according  to  the  nerve  injured 
and  the  degree  of  the  injury.  Occasionally,  when 
the  nerve  is  lacerated,  pain  may  arise  in  the  distri- 
bution of  the  aifected  nerve  a  few  days  after  the 
injury  [vide  p.  43). 

In  secondary  injury  the  nerves  become  involved 
in  fibrous  tissue,  or  compressed  by  exuberant  callus 
or  bone.  The  musculo-spiral  is  the  nerve  most  often 
affected  in  this  way.  The  interference  with  the 
functions  of  the  nerve  may  arise  many  years  after 
the  fracture,  as  occurs  in  the  late  involvement  of 
the  ulnar  nerve  after  fractures  in  the  region  of  the 
elbow-joint  {vide  p.  256). 

Primary  injury  is  rarer  than  secondary,  but  it  is 
diificult  to  obtain  the  exact  percentage,  for  it  often 
happens  that  no  examination  for  nerve  injury  was 
made  before  the  limb  was  put  in  splints  and  the  fact 
of  the  injury  is  first  discovered  on  their  removal  ;  in 
by  far  the  greater  number  of  cases  also,  no  operation 


COMPLICATINa    DISLOCATIONS  9 

is  necessary,  so  that  the  exact  condition  of  the  nerve 
is  a  matter  of  conjecture. 

In  both  primary  and  secondary  injuries  the 
division  is  more  often  incomplete  than  complete,  and 
even  in  the  primary  form,  more  often  physiological. 

In  every  instance  of  fracture  careful  examination 
should  be  carried  out  before  the  limb  is  put  up. 

The  musculo-spiral  nerve  suffers  most  often  in  the 
upper  limb,  the  external  popliteal  in  the  lower. 
Bruns  found  the  order  of  frequency  to  be  as  follows  : 
Out  of  189  cases  of  involvement  of  nerves  in  frac- 
tures 77  were  instances  of  musculo-spiral,  25 
external  popliteal,  19  ulnar,  and  17  median.  All 
others  were  rare.  These  figures  correspond  to  the 
relative  frequency  in  the  patients  with  nerve  injuries 
complicating  fracture  which  have  been  treated  at 
the  London  Hospital. 

Nerve  injury  complicating  dislocations. — As  in  the 
nerve  injuries  complicating  fractures  the  injury  may 
be  primary  or  secondary.  The  primary  may  be 
caused  by  the  direct  pressure  of  the  head  of  the 
bone  at  the  moment  of  dislocation,  arise  during 
attempts  at  its  reduction,  or  may  be  due  to  the 
violence  which  caused  the  dislocation. 

Secondary  involvement  occurs  only  in  unreduced 
dislocations,  and  is  due  to  the  long-continued 
pressure  of  the  head  of  the  bone,  or  to  inflammator}^ 
chansfes  around  it. 

Both  primary   and  secondcary   involvement  is  met 


10  INJURIES    OF    NERYES 

with  most  often  as  a  complication  of  subcoracoid 
dislocation  of  the  hmnerusj  and  is  by  no  means  an 
uncommon  accident.  The  brachial  j^lexus  or  the 
nerves  arising  from  it  are  injured^  in  most  cases  the 
plexus  itself.  The  whole  plexus  may  be  injured,  but 
it  is  usually  the  inner  cord  alone,  or  to  the  greatest 
degree.  The  whole  plexus  sometimes  suffers  in 
injudicious  attempts  at  reduction  by  the  "  heel  in 
axilla"  method.  In  subglenoid  dislocations  the 
circumflex  or  musculo-spiral  nerve  may  be  injured. 
The  ulnar  nerve  is  sometimes  injured  in  dislocations 
of  the  elbow,  the  posterior  interosseous  in  forward 
dislocations  of  the  head  of  the  radius,  and  the 
great  sciatic  or  obturator  nerve  in  dislocations  of 
the  hip. 

Nerve  injuries  complicating  surgical  procedures. — 
It  is  still  by  no  means  uncommon  to  find  a  localised 
paralysis  resulting  from  surgical  procedures  carried 
out  under  a  general  anaesthetic.  The  majority  of  these 
fall  into  the  group  of  "  post-anaesthetic  paralyses," 
due  to  the  position  of  the  patient.  But  in  a  few, 
the  operative  manipulations  of  the  surgeon  are  re- 
sponsible; such  are  the  injuries  to  the  brachial  plexus, 
following  the  reduction  of  a  dislocation  of  the 
humerus  by  the  ''  heel  in  axilla  "  method,  or  of  the 
great  sciatic  or  its  external  popliteal  branch  from 
manipulation  of  a  congenital  dislocation  of  the  hip, 
or  the  reduction  of  an  acquired  dislocation,  or  the 
large  number  of   injuries  resulting   from  wounds   of 


POST- ANAESTHETIC    PARALYSIS         11 

nerves.  These  have  already  been  referred  to  in 
their  appropriate  sections. 

The  cases  in  which  no  manipulative  cause  can  be 
assigned  fall  into  two  groups.  The  first,  which  is 
uncommon,  includes  the  injuries  resulting  from 
direct  pressure ;  such  are  injury  to  the  musculo- 
spiral,  due  in  most  cases  to  the  direct  pressure  of  the 
edge  of  the  table,  or  injury  to  the  external  popliteal 
nerve,  from  the  application  of  a  Clover's  crutch  or 
Esmarch's  bandage. 

In  the  second  group  are  the  traction  injuries. 
The  brachial  plexus  of  the  right  side  suffers  most 
often,  and  the  muscles  supplied  by  the  fifth  cervical 
nerve  are  usually  paralysed  alone;  if  muscles  supplied 
by  other  nerves  suffer  as  well,  those  supplied  by  the 
fifth  are  always  the  most  severely  affected. 

This  type  of  injury  can  only  occur  when  the 
patient\s  arm  is  abducted  from  the  body  or  raised 
above  the  head  ;  in  none  of  the  recorded  cases  did 
it  follow  an  operation  in  which  the  arms  were  kept 
to  the  side.  It  most  often  happens  when  the  right 
arm  has  been  abducted  and  externally  rotated,  and 
the  patient,  for  the  convenience  of  the  surgeon,  has 
been  brought  to  the  edge  of  the  table  ;  in  this  way 
the  weight  of  the  upper  limb  falls  on  the  brachial 
plexus  and  its  cords  are  stretched. 

In  a  few  cases  the  paralysis  follows  elevation  of 
the  arms  above  the  head  ;  in  these  the  nerves  may 
be  injured  as  the  result  of  the  direct  pressure  of  the 


12  INJURIES    OF    NEEYES 

liead  of  the  liumerus  over  wliich.  tliey  lie.  It  lias  been 
suggested  that  the  injury  is  due  to  the  nerves  being 
crushed  between  the  clavicle  and  first  rib  or  trans- 
verse process  of  cervical  vertebree;  this  is  improbable. 
The  violence  results  most  often  in  incomplete 
physiological  division_,  and  the  majority  of  the  cases 
recover  without  active  suro-ical  interference.      In  all 

o 

the  patients  that  have  come  under  my  notice_,  spon- 
taneous recovery  occurred^  and  I  have  been  able  to 
find  record  of  one  case  only  in  which  recovery  was 
incomplete.  In  this  patient  the  deltoid  remained 
permanently  jDaralysed. 

These  paralyses  occurring  after  a  routine  abdominal 
operation^  are  a  reproach  to  all  concerned,  and  not 
to  the  anaesthetist  alone_,  to  whom  the  blame  is  often 
imputed.  They  are  ^preventable  in  most  cases,  and 
thought  must  be  taken  to  avoid  attitudes  which  are 
likely  to  produce  injury  to  nerves,  and  particular 
care  exercised  to  avoid  undue  abduction  or  elevation 
of  the  arms. 

Gunshot  wounds  of  nerves. — The  recent  wars  in 
South  Africa  and  the  Far  East  have  added  much  to 
our  knowledge  of  these  injuries.  Makins,  in  his 
Stirgical  Ex'periences  in  South  Africa,  states  that  ^Hhe 
occurrence  of  these  injuries  has  undoubtedly  increased 
in  frequency  with  the  employment  of  bullets  of  small 
calibre.^^  This  was  also  noticed  in  the  Russo-Japanese 
war  and  recorded  by  Hashimoto  and  Tokuoka. 

It  is  impossible  to  give   the  exact   frequency  with 


GUNSHOT    WOUNDS  13 

whicli  the  various  nerves  were  injured^  but  of  those 
cases  needing  prolonged  treatment  or  operation  the 
great  sciatic  suffered  most  often^  next  in  frequency 
the  musculo-spiral.  Thus,  out  of  38  cases  treated 
by  Hashimoto  and  Tokuoka,  18  were  sciatic,  16 
musculo-spiral,  2  median,  1  ulnar,  and  1  posterior 
tibial.  The  comparative  frequency  agrees  fairly 
well  with  that  of  the  cases  that  have  come  under 
my  observation,  with  the  exception  that  injuries  of 
the  brachial  j^lexus  and  the  nerves  arising  from  it 
were  more  often  met  with. 

The  sciatic  suffered  most  often  from  a  primary 
injury,  the  musculo-spiral  in  fractures  of  the  humerus 
in  a  greater  percentage  of  cases  than  seen  in  fractures 
of  this  bone  in  civil  life. 

In  a  large  number  of  cases  the  injury  is  an 
incomplete  physiological  division,  primary,  or  secon- 
dary, from  involvement  in  fibrous  tissue  or  callus. 
The  temporary  loss  of  conductivity,  complete  or  in- 
complete, not  uncommonly  met  with  when  the  track 
of  the  bullet  passes  near  one  of  the  peripheral 
nerves,  is  an  example  of  primary  incomplete 
physiological  division.  Complete  anatomical  division 
is  rare.  In  many  instances  the  wound  does  not 
completely  divide  the  nerve,  but  the  signs  of  com- 
plete division  develop  later  from  the  resulting 
fibrosis,  and  indicate  operative  treatment.  In  other 
cases  pain  and  tenderness  {vide  p.  134)  occur, 
rendering  neurectomy  necessary. 


14  mJURIES    OF    NERVES 

Several  instances  have  been  recorded  in  wliicli  a 
nerve  was  penetrated  by  a  bullet,  tlie  nerves  of  tlie 
brachial  plexus  and  tlie  great  sciatic  most  often, 
without  producing  even  complete  physiological  divi- 
sion. One  case  has  come  under  my  notice  in  which 
the  median  nerve  was  so  affected  without  any  per- 
manent interference  with  conduction. 


CHAPTER    II 

Symptoms  following  tlie  Complete  Division  of  a  Peripheral  Nerve 
— Changes  in  Sensibility  produced  by  Division  of  a  Peripheral 
Nerve — Three  Systems  of  Afferent  Fibres — Changes  in  Sensi- 
bility resulting  from  Division  of  Posterior  Eoots — Division  of 
a  Nerve  "  without  Sensory  Change  " — Changes  in  the  Muscles 
following  Complete  Division  of  their  Motor  Nerve — Paralysis 
— Electrical  Changes— Changes  in  the  Skin,  Nails,  Hair, 
Bones,  and  Joints. 

Complete  division  of  a  mixed  peripheral  nerve 
results  in  the  loss  of  those  forms  of  sensibility  which 
it  ^^exclusively"  supplies^  and  paralysis  of  the 
muscles  to  which  it  sends  motor  fibres. 

Changes  in  sensibility. — Section  of  a  sensory  nerve 
enables  us  to  map  out  its  "  exclusive  "  supply,  that 
is,  the  area  to  which  it  alone  sends  fibres ;  it  gives 
no  information  with  regard  to  the  much  larger  area 
to  which  it  supplies  fibres  in  common  with  other 
nerves.  To  obtain  this,  its  "  full  "  supply,  we  must 
study  the  sensibility  remaining  after  » division  of 
the  surrounding  nerves  ;  this  method  of  residual 
sensibility  or  residual  sesthesia,  first  employed  by 
Mr.  Jonathan  Hutchinson  sen.,  to  map  out  the  dis- 
tribution of  the  median  nerve  on  the  dorsal  surface 
of  the  fingers,  has  in  the  hands  of  Sherrington  given 
valuable  results  in  experimental  work. 


16  INJUEIES    OF    NEEYES 

The  area  of  full  supply  deduced  from  residual 
sensibility  corresponds  closely  to  tlie  extent  of  skin 
wliicli  becomes  tender  on  stimulation  of  the  trunk  of 
the  nerve.  This  was  done  experimentally  by  Weir 
Mitchell^  whO;  following  the  example  of  Waller, 
stimulated  the  ulnar  nerve  behind  the  internal  con- 
dyle with  a  mixture  of  ice  and  salt.  He  experienced 
an  intense  burning  pain  over  an  area  larger  than 
that  which  later  became  anaesthetic  as  the  result  of 
the  continued  action  of  the  freezing  mixture.  Most 
peripheral  nerves  are  too  deeply  seated  to  admit  of 
this  method  of  stimulation.  But  after  certain  in- 
complete injuries,  particularly  those  due  to  gunshot 
wounds  {vide  p.  134),  marked  tenderness  may  arise  in 
the  territory  to  which  the  injured  nerve  sends  fibres. 
This  is  always  more  widespread  than  the  loss  of 
sensibility  which  results  from  its  therapeutic  division 
and  corresponds  to  its  full  supply. 

After  section  of  a  mixed  nerve,  such  as  the 
median  at  the  wrist,  if  no  tendons  have  been  divided 
at  the  same  time,  the  patient  is,  in  most  cases, 
able  to  appreciate  those  stimuli  commonly  called 
tactile ;  a  tC)uch  with  the  finger,  a  23encil,  or  a  piece 
of  paper  may  be  not  only  readily  distinguished  but 
accurately  localised.  When  pricked  with  a  pin 
the  patient  recognises  that  he  has  been  touched  but 
fails  to  perceive  the  sharpness  of  the  stimulus.  Any- 
thing-, in  fact,  which  deforms  the  skin  produces  an 
effect  on  consciousness.     To  this   form  of   sensibility 


DEEP    SENSIBILITY 


17 


which  persists  after  the  division  of  all  the  cutaneous 
nerves  supplying  the  skin^  Dr.  Head  and  the  author 
gave  the  name  of  ''  deep  sensibility "  or  ^^  deep 
touch/^  The  fibres  which  convey  this  form  of  sensi- 
bility have  widespread  anastomoses  and  run  for  the 
most  part  with  the  motor  nerves  to  the  muscles  and 
along  their  tendons  and  other  fibrous  structures  to 
the  bones^  periosteum  and  ligaments.       While   deep 


Fig.  1. — To  illustrate  the  loss  of  sensibility  resulting  from 
division  of  a  peripheral  nerve.  The  area  of  loss  of  sensi- 
bility to  light  touch  is  bounded  by  a  line;  the  shaded 
portion  represents  the  area  of  loss  of  sensibility  to  prick 
and  all  degrees  of  temperature.  The  unshaded  poi-tion 
rejDresents  the  "  intermediate  zone." 


sensibility  is  present  the  patient  is  able  to  recognise 
the  position  into  which  his  joints  have  been  placed. 
Through  this  deep  system  the  patient  is  also  able  to 
appreciate  increase  of  pressure  and  the  pain  of  deep 
pressure,  this  being  ill  defined  and  often  compared 
by  the  patient  to  that  produced  by  bruising  a  bone. 

2 


18  INJURIES    OF    XEEYES 

The  sharpness  of  a  stimulus^  a  prick  with  a 
sharp  needle  and  all  degrees  of  temperature  are  not 
recosrnised  over  an  area  which  varies  somewhat  from 
patient  to  patient  {vide  Fig.  1). 

Surrounding  this  area  and  corresponding  closely 
to  the  distribution  of  the  nerve  as  figured  in  ana- 
tomical text-books  is  a  territory  within  which  the 
patient  is  unable  to  appreciate  liglit  touches  with 
cotton-wool  and  to  discriminate  between  temperatures 
of  about  22°  C.  and  38°  C.  (called  minor  degrees)^  and 
fails  to  distinguish  as  two^  the  points  of  a  pair  of 
compasses  when  separated  to  many  times  the  dis- 
tance necessary  over  the  corresponding  part  of  the 
sound  limb  or  the  unaffected  portion  of  the  injured 
(compass  test) .  The  boundary  of  this  loss  of  sensi- 
bility to  light  touch  is  well  defined  and  liable  to 
very  little  variation  even  when  many  patients  are 
examined. 

Within  the  area  between  the  border  of  the  loss  of 
sensibility  to  prick  and  the  loss  of  sensibility  to 
light  touch  (called  the  intermediate  zone),  the 
patient  is  able  to  appreciate  the  sharpness  of  a 
pin-prick  and  to  differentiate  between  water  below 
about  20°  0.  and  water  above  about  45°  0.  All  stimuli 
in  this  zone  appear  to  have  an  unpleasant  tingling, 
diffuse  character.  A  prick  causes  a  sensation  of 
pins  and  needles,  which  radiates  widely;  the  patient 
often  withdraws  his  hand,  describing  the  sensation  as 
a     "  numb,     tingling    pain,"    or    "  as    if    you    were 


INTERMEDIATE   ZONE  19 

touching  a  sore  place/^  and  rubs  the  part ;  this  pain 
may  persist  for  a  considerable  time.  Changes  in 
atmospheric  temperature  affect  this  portion  of  the 
skin  very  readily,  the  slightest  coldness  in  the 
weather  causes  the  part  to  become  cold  and  blue, 
and  of  this  the  patient  bitterly  complains.  On 
jDalpation  it  feels  definitely  colder  than  tlie  sound 
portion   of  the   limb. 

The  boundary  of  this  intermediate  zone  may  be 
marked  out  by  dragging  a  sharp  needle  across  the 
skin  from  normal  towards  abnormal  j^arts ;  imme- 
diately the  boundary  of  the  loss  of  sensibility  to 
lio'ht  touch  is  reached  a  marked  chang-e  in  sensi- 
bility  is  noticed  by  the  patient,,  the  sensation  pro- 
voked having  the  characteristics  just  described. 
This  is  spoken  of  as  the  "  line  of  change  to  prick  ^^ 
[vide  also  incomplete  division,  p.  38). 

We  see,  then,  that  complete  division  of  a  mixed  or 
sensory  nerve  causes  a  well-defined  loss  of  sensibility 
to  light  touch,  which  varies  little  from  patient  to 
patient  and  an  ill-defined  and  smaller  area  of  loss  of 
sensibility  to  prick,  which  varies  within  wide  limits, 
sometimes  being  almost  as  extensive  as  the  loss  of 
sensibility  to  light  touch,  at  others  falling  far  short 
of  it.  The  outline  of  the  area  of  loss  of  sensibility 
to  prick  may  also  vary  somewhat  in  the  same  patient; 
on  a  bright,  warm  day  it  will  be  a  little  smaller 
than  on  a  cold,  damp  one,  and  may  vary  with  the 
state  of  the  patient's  health.      But  this  variation  is 


20  INJUEIES    OF    NERVES 

sliglit  only,  and  is  easily  overlooked  unless  the  con- 
dition is  charted  each  time  the  patient  is  examined. 
A  loss  of  sensibility  to  deep  touch  may  be  present  if 
the  nerve  has  been  divided  above  all  its  motor 
branches^  or  if  tendons  have  been  severed  in  addition 
to  the  nerve^  but  is  rarely  as  extensive  as  the  loss 
of  sensibility  to  prick. 

Hence  we  see  that  division  of  a  nerve  rarely 
produces  an  area  of  loss  of  all  forms  of  sensibility; 
deep  touch  can  usually  be  appreciated  everywhere 
and  the  only  loss  of  sensibility  at  all  corresponding 
in  extent  to  that  usually  assigned  to  the  nerve^  is  the 
loss  of  sensibility  to  light  touch.  For  these  and 
other  reasons  the  afferent  fibres  in  a  peripheral 
nerve  may  be  divided  into  three  systems,  as  sug- 
gested by  Dr.  Head  and  the  author.  These  have  the 
following  characteristics  : 

(1)  Those  which  subserve  deep  sensibility.  These 
conduct  impulses  produced  by  pressure;  its  gradual 
increase  can  be  perceived  and  the  pain  produced  by 
excessive  pressure  recognised.  Through  this  system 
the  patient  recognises  the  extent  and  direction  of 
the  movements  of  joints  and  muscles.  These  fibres 
run  mainly  with  the  motor  nerves,  have  widespread 
anastomoses,  and  are  not  destroyed  by  division  of  all 
the  sensory  nerves  to  the  skin. 

(2)  Those  responding  to  painful  cutaneous  stimu- 
lation and  to  the  extreme  degrees  of  temperature. 
To  this  system  of  fibres  and  end  organs  we  gave  the 


EPICEITIC,  PROTOPATHIC  SENSIBILITY  21 

name  "  protopathic."  All  sensations  evoked  by  the 
stimuli  to  wliicli  this  system  is  capable  of  reacting 
are  badly  localised^  radiate  widely  and  are  accom- 
panied by  tingling.  It  is  the  form  of  sensibility 
which  exists  in  the  intermediate  zone^  between  the 
boundary  of  loss  of  all  forms  of  cutaneous  sensibility 
and  that  of  the  loss  of  sensibility  to  light  touch. 
Reflex  movements  owe  their  origin  to  this  system, 
which  produces  a  rapid  response  unaccompanied  by 
any  definite  appreciation  of  the  spot  stimulated. 

(3)  A  system  of  nerve-fibres  and  end  organs  res- 
ponding to  light  touches  with  a  well-localised  sensa- 
tion. Through  it  minor  degrees  of  temperature  are 
differentiated  and  two  |)oints  discriminated.  To  this 
system  we  gave  the  name  of  "  epicritic." 

In  describing  the  loss  of  sensibility  which  results 
from  the  division  of  individual  nerves  I  shall  employ 
these  three  headings,  and  use  the  terms  ^^  epicritic  " 
and  "  protopathic ''  sensibility  as  synonymous  with 
sensibility  to  light  touch  and  to  prick.  These  last 
two  forms  of  sensibility  are  differently  represented 
in  each  peripheral  nerve,  but  in  all  cases  the  fibres 
subserving  protopathic  sensibility  have  a  much  wider 
overlap  than  those  which  subserve  epicritic  sensibility. 

The  investigation  of  the  distribution  of  deep  sen- 
sibility is  beset  with  many  difficulties  ;  it  can  only  be 
examined  in  cases  in  which  all  cutaneous  sensibility 
is  absent.  It  is  impossible  at  present  to  formulate 
any  further  hypothesis  with  regard  to  its  distribution. 


22  INJURIES    OF    NEEYES 

Mucli  difference  of  opinion  lias  existed  with  regard 
to  tlie  loss  of  sensibility  wliicli  results  from  division 
of  a  peripheral  nerve.  It  was  pointed  out  by  Richet, 
in  1867^  that  sensibility  may  be  retained  after  divi- 
sion of  the  median  nerve ;  many  similar  cases  have 
been  recorded^  and  I  have  known  good  observers  in 
other  branches  of  surgery  overlook  the  fact  of  divi- 
sion of  this  nerve. 

The  method  used  by  Richet  in  testing  sensibility 
explains  why  no  loss  could  be  discovered.  An 
account  of  it  has  been  preserved  in  a  letter  written 
to  the  Lancet  by  Lockhart  Clarke,  in  which  he 
stated  "with  a  piece  of  paper  rolled  up  into  the  form 
of  a  stick  he  (Richet)  tickled  in  the  most  perplexing 
Avay  different  parts  of  the  fingers  and  palm  supplied 
by  the  median  nerve.  .  .  .  Nevertheless  sensi- 
bility, though  not  abolished,  was  somewhat  imj)aired, 
as  was  evident  when  a  pin  was  used  instead  of  pajDer 
to  excite  the  skin.  The  application  of  heat  and  cold 
was  not  attended  with  very  satisfactory  results.^^ 
It  is  quite  evident  that  the  ordinary  loss  of  sensi- 
bility produced  by  division  of  the  median  nerve  Avas 
present  in  this  case  with  retention  of  dee^o  sensibilit3^ 
Similar  methods  of  testing  have  led  to  similar  errors 
in  numberless  cases  since. 

Richet  considered  that  tlie  retention  of  sensibility 
was  duo  to  tlic  |)resence  of  tlio  recurrent  fibres 
described  Ijy  Claud  Bernard.  The  next  year,  Savcny 
explained    tlie    phenonjcnon     as     it    occurred    after 


SUPPLEMENTARY    SENSIBILITY  23 

division  of  the  musculo-spiral  nerve  by  the  presence 
o£  anastomoses  with  neighbouring  nerves.  In  the 
same  year  Letievant  enunciated  his  wider  theory, 
that  of  supplementary  sensibility  {.sensibilite  siqoplece) , 
including  in  the  term  not  only  recurrent  sensibility 
and  anastomoses,  or,  as  he  expressed  it,  copa'se  and 
fine  anastomoses,  but  also  sensibility  taken  up  from 
an  ansesthetic  region  by  the  end  organs  of  the 
neighbouring  sound  skin,  called  by  him  "  mediate 
sensibility,^^  and  corresponding  in  its  characteristics 
to  that  form  of  sensibility  to  which  we  gave  the 
name  of  "  deep/^  His  researches  received  apparent 
confirmation  from  the  researches  of  Arloino-  and 
Tripier,  published  the  following'  year. 

In  1873  Letievant  published  his  work,  Traite  des 
Sections  Nerveuses,  in  which  he  gave  an  extended 
account  of  his  doctrine  applied  to  the  various  nerves. 
Richelot,  and  more  recenth^,  Laborde,  confirmed  his 
observations,  while  most  modern  writers  on  the  sub- 
ject have  taken  supplementary  sensibility  as  the 
explanation  of  the  varieties  of  loss  of  sensibility  met 
with  after  division  of  a  nerve.  But  however  widely 
applied,  this  fails  to  explain  the  well-defined  and 
little  varying  loss  of  epicritic  sensibility,  the  varying 
protopathic  loss,  the  presence  of  deep  sensibility  and 
the  curious  dissociation  of  sensibility  seen  after 
division  of  j^osterior  roots  and  certain  nerves  of  the 
dorsum  of  the  hand  {vide  p.  241)  in  which  light  touch 
and  the  minor  degrees  of  temperature  can  be  appre- 


24  IXJUEIES    OF    XERYES 

ciated  over  a  part  insensitive  to  protopathic  stimuli. 
It  also  leaves  unexplained  the  method  of  sensory- 
recovery  {vide  pp.  lOlj  123).  These  can  be  most 
satisfactorily  explained  by  the  theory  brought  for- 
ward by  Dr.  Head  and  the  author. 

The  loss  of  sensibility  present  immediately  after 
the  injury  remains  unchanged  until  regeneration  of 
the  peripheral  end  and  reunion  with  the  central 
nervous  system  takes  place.  There  is  no  gradual 
encroachment  upon  the  anaesthetic  area  by  the 
nerves  supplying  the  surrounding  skin.  In  cases  of 
secondary  suture  performed  some  weeks  after  section^ 
if  any  improvement  in  sensibility  has  taken  place^ 
freeing  and  freshening  the  ends  of  the  nerve  results 
in  the  sensory  loss  becoming  identical  with  that 
which  was  present  immediately  after  the  accident ; 
all  the  restoration  in  sensibility  has  been  due  to 
reunion  with  the  central  nervous  system.  This 
reunion  may  be  through  divided  nerve  branches  in 
the  surrounding  tissues  and  not  through  its  own 
central  end^  but  this  does  not  take  place  to  any  great 
extent  in  adults. 

Division  of  posterior  roots. — The  effect  of  the  divi- 
sion of  posterior  roots  throws  a  further  light  upon 
the  sensory  distribution  of  the  peripheral  nerves. 
A  knowledge  of  the  nature  of  this  distribution  is  of 
extreme  importance  in  diagnosis. 

Division    of    posterior   roots  produces  an  area  of 
loss  of  protopathic  sensibility  larger  than  the  area 


DIVISION   OF    POSTERIOR   ROOTS 


25 


of  loss  of  light  toucli  (vide  Fig.  2).  A  territory, 
therefore,  remains  within  which  the  patient  is  unable 
to  appreciate  the  sharpness  of  a  prick  or  the  extreme 
degrees  of  temperature,  but  is  able  to  recognise  stimu- 
lation with  cotton- wool,  and  may  be  able  to  discrimi- 
nate between  warm  and  cool,  although  totally  unable 
to  detect  any  difference  between  ice  and  water  at 
55°  C. 


Fig.  2. — To  illustrate  the  loss  of  sensibility  resulting  from 
division  of  posterior  roots.  In  this  patient  (Head  and 
Sherren,  No.  52)  the  fifth,  sixth,  seventh,  and  eighth 
cervical,  and  first  and  second  dorsal  posterior  roots  were 
divided.  The  thick  continuous  line  represents  the  area 
insensitive  to  prick  ;  the  thin  dotted  line  the  area  insensi- 
tive to  light  touch.  A  represents  area  within  which  light 
touches  with  cotton-wool  were  appreciated,  but  painful 
stimulation  was  unrecooiiised. 


The  peripheral  nerve  may  be  looked  upon  as  the 
unit  of  epicritic  supply,  the  posterior  root  as  the 
unit;  of  protopathic  supply.  The  nearer  a  peripheral 
nerve  represents  the  supply  of  one  or  more  posterior 
roots,  the  more  definite  will  be  the  borders  of  the 
loss  of  sensibility  to  prick  produced  by  dividing  that 
nerve,  and  the  more   nearly  will  the    loss  of   proto- 


26  I]S[JUEIES    OF     NERYES 

jDatliic  correspond  to  the  loss  of  epicritic  sensibility. 
For  example,  tlie  external  popliteal  nerve  {vide  p.  297) 
corresponds  closely  to  tlie  distribution  of  tlie  fifth 
lumbar  root_,  its  division  produces  a  widespread  and 
well-defined  loss  of  protopathic  sensibility  corres- 
ponding almost  exactly  to  the  area  of  epicritic  loss. 
The  median  nerve,  on  the  other  hand,  represents  the 
supply  of  no  single  ^Dosterior  root,  but  contains 
sensory  fibres  from  the  seventh  and  eighth  cervical, 
and  possibly  also  from  the  sixth  cervical  and  the 
first  dorsal  nerves ;  consequently  its  division  will 
produce  loss  of  protopathic  sensibility  over  the 
relatively  small  area  to  which  this  nerve  carries  all 
the  protopathic  supply  (its  exclusive  supply). 

Division  of  peripheral  nerves  without  sensory  change. 
— There  are  certain  nerves  which  can  be  divided  in 
certain  situations  without  producing-  sensory  change 
that  can  be  appreciated  by  any  of  our  present 
methods  of  testing.  These  are,  the  musculo=spiral 
in  the  lower  third  of  the  arm,  that  is,  below  the 
point  at  which  its  external  cutaneous  branches  are 
given  off,  the  radial  nerve  in  the  upper  two  thirds 
of  the  forearm,  and  certain  of  the  anterior  primary 
divisions  of  the  cervical  nerves  which  enter  into  the 
formation  of  the  brachial  jjloxus.  These  nerves 
supply  no  area  of  skin  exclusively  with  any  form  ot" 
sensibility,  hence  division  of  other  branches  in  addi- 
tion is  necessary  to  produce  any  sensory  loss. 

Motor  symptoms. — Couiplete    division   of    a    nerve 


MOTOR    SYMPTOMS  27 

containing  motor  fibres  results  in  immediate  paralysis 
of  the  muscles  supplied  by  it.  But  this  paralysis  is 
not  always  obvious^  and  its  detection  may  require 
careful  examination.  No  movement  ordinarily  em- 
ployed in  daily  life  is  the  result  of  the  contraction 
of  one  muscle  only ;  in  investigating  the  paralysis  of 
muscles  after  a  nerve  injury  this  must  be  remem- 
bered. It  is  the  action  of  the  individual  muscles 
that  must  be  investigated^  not  the  movements  with 
which  their  contraction  is  usually  associated.  For 
example^  after  division  of  the  median  nerve  at 
the  wrist;  the  action  of  the  abductor  and  oppo- 
nens  pollicis  muscles  must  be  investigated^  not  the 
presence  or  absence  of  abduction  and  opposition, 
these  movements  can  be  imitated  by  the  contraction 
of  other  muscles.  Again,  extension  of  the  fingers 
in  a  line  with  the  hand  is  due  to  the  contraction  of 
the  extensors  of  the  fingers,  supplied  by  the  musculo- 
spiral  nerve,  of  the  flexors  of  the  wrist  supplied  by 
the  median  and  ulnar,  and  of  the  interossei  muscles 
supplied  by  the  latter  nerve.* 

That  mistakes  might  arise  in  this  way  was  first 
pointed  out  by  Swan  in  1834,  in  recording  the 
results  of  his  experiments.  He  wrote  :  '^  I  was  at 
first  astonished  at  seeing  how  much  an  animal  could 
move  its  limb  a  short  time  after   operation   (division 

*  Those  iuterested  in  the  subject  of  aniscular  movements  will 
tiud  ii  full  account  in  Dr.  C.  E.  Beevor's  Croonian  Lectures,  delivered 
in  1UU3. 


28  INJURIES    OF    NERVES 

of  sciatic  nerve)^  and  concluded  that  misconceptions 
have  arisen  from  considering  the  general  motion  of 
the  limb  as  evidence  of  the  regeneration  of  the 
nerve /^  Letievant^  nearly  forty  years  later^  de- 
veloped this  and  named  the  movements  "  supple- 
mentary/^ He  speaks  of  supplementary  motility 
(motilite  suppleee),  meaning  thereby  the  imitation 
by  unaffected  muscles  of  movements  usually  associated 
with  contraction  of  the  paralysed  muscles. 

The  affected  muscles  atrophy  Avith  a  greater  or 
less  rapidity  according  to  the  means  used  to  keep 
up  their  nutrition^  and  unless  care  be  taken  may 
become  converted  into  a  mass  of  fibro-fatty  material 
devoid  of  all  contractile  power. 

Unless  precautions  are  taken  they  become  over- 
stretched by  the  action  of  the  opposing  muscles, 
and  these  latter  become  permanently  contracted — 
conditions  that  seriously  interfere  with  complete 
recovery. 

Electrical  changes. — Muscles  in  communication  with 
healthy  anterior  horn  cells  respond  readily  and 
briskly  when  stimulated  with  the  interrupted  (faradic) 
and  the  constant  (galvanic)  currents.  With  the 
former  current,  Avhen  the  interruptions  are  rapid 
the  muscle  remains  contracted  as  long  as  the  current 
is  passing;  with  the  latter,  a  brisk  twitch  occurs  at 
the  moment  the  current  is  made  or  broken,  but  no 
contraction  is  evoked  while  the  current  is  passing 
through  the  muscle.      A  contraction  is  produced  by 


ELECTRICAL    CHANGES  29 

the  smallest  amount  of  current  when  the  kathode  is 
used  as  the  testing  electrode  and  the  current  is 
closed  (K.C.C.),  then  when  the  anode  is  used  and 
the  current  closed  (A.C.C.). 

After  division  of  its  motor  nerve,  a  muscle  ceases 
to  respond  to  stimulation  with  the  interrupted 
current  applied  over  its  motor  point  in  from  four  to 
seven  days.  At  about  the  tenth  day  it  may  be 
exceedingly  difficult  to  obtain  any  contraction  to  the 
constant  current,  and  at  or  about  this  time  the 
muscles  respond  to  this  form  of  stimulation  with  a 
sluggish,  wave-like  contraction  starting  at  the  spot 
stimulated,  and  a  stronger  current  must  be  used  to 
call  it  forth  than  on  the  sound  side.  The  contraction 
appears  first  at  the  closing  of  the  circuit,  when  the 
anode  is  used  as  the  testing  electrode  (A.C.C.  > 
K.C.C.),  but  this,  although  usual,  is  probably  not 
invariable.  To  loss  of  irritability  to  the  interrupted 
current  with  this  specific  alteration  in  the  type  of 
the  contraction  given  to  stimulation  with  the  con- 
stant current  the  name  ^^  reaction  of  degeneration  ^' 
(R.D.)  is  applied.  The  name  should  be  reserved  for 
this  one  type  of  reaction  and  terms  such  as  "  partial 
n.J)."  avoided. 

The  length  of  time  after  separation  from  their 
anterior  horn  cells  that  the  muscles  retain  the 
power  of  reacting  to  stimulation  with  the  constant 
current  varies  ;  so  long  as  contractile  substance  is 
present  in  the  "  muscles  "  they  will  respond  to  this 


30  INJURIES    OF    NERVES 

stiuinlus.  When  once  a  nmscle  lias  lost  the  power  of 
responding  to  this  current  its  recovery  is  impossible. 
But  great  care  is  necessary  before  coining  to  this 
conclusion,  for  contraction  may  be  evident  at  one 
examination  and  not  at  another.  Purves  Stewart  has 
recorded  a  case  in  which  the  muscles  responded  to 
stimulation  with  the  constant  current  sixteen  years 
after  separation  from  its  nerve-centre,  and  I  have 
recently  seen  a  patient  in  Avliom  the  muscles  reacted 
to  the  constant  current,  although  the  musculo-spiral 
nerve  had  been  divided  twenty-three  years. 

Changes  in  the  skin. — When  one  of  the  nerves  of 
the  palm  is  divided  the  superficial  layers  of  the  epi- 
thelium no  longer  desquamate  so  readily  over  the  area 
of  loss  of  sensibility  to  prick.  This  is  well  seen  in 
a  patient  who  does  manual  work,  and  is  a  striking 
feature  in  the  progress  of  a  case  of  primary  suture. 
On  removing  the  first  dressing  the  normal  parts  of 
the  hand  protected  by  the  cotton-wool  are  soft  and 
the  epithelium  sodden,  but  over  the  abnormal  area 
the  epithelium  has  not  been  shed  and  presents  a 
rough,  dry  layer  marking  out  the  affected  area  (vide 
Plate  I).  If  the  hand  be  well  soaked  the  dry  epi- 
thelium can  be  peeled  off,  exposing  wrinkled,  pinkish- 
blue  skin,  colder  than  normal.  This  area  does  not 
sweat.  A  prick  bleeds  more  readily  than  elsewhere 
and  leaves,  as  first  pointed  out  by  Israel,  a  red  spot 
or  papule,  which  may  persist  for  many  hours,  or 
even  days.      This  is  most  striking,  and  the  marks  of 


PLATE  I. 


Taken  three  weeks  after  division  of  the  uhiar  nerve  to  sliow  the 
delayed  desquamation  over  the  ulnar  portion  of  the  palm  of  the  hand. 
The  area  enclosed  by  the  line  represents  the  area  insensitive  to  light 
touch. 


To  face  p.  30. 


Adlard  Jf-  Sou,  Impr, 


PLATE   II. 

To  illustrate  the  formation  of  "  trophic  ulcers." 


Fig.    1. — Shows   a   blister  on   the   dorsal  surface  of   middle  finger 
following  an  injury  to  the  median  nerve. 


Fig.  2. —The  blister  is  shown  separating  and  leaving  a  raw,  red  surface. 


Tof(u-i'  I,.  -.'A. 


AcUurd  4'  Son,  Impr. 


PLATE    III. 

To  illustrate  the  formation  of  "  trophic  ulcers." 


Fig   1  —Shows  destrnction  uf  the  tip  of  the  index  finger  by  an  ulcer, 
general  thickening  of  this  finger  and  the  ulcer  on  the  middle  finger. 


Note  the 


ihows  the  hand  of  the  same  patient  two  years  later,  after  secondary 
had  been  performed  and  protopiithic  sensibility  had  been  restored. 
M-ation  spreail  and  necessitated  ami)utation  of  the  terminal  phalanx  of 


Fig.  2.— Shows 
suture   ha( 

The  idceration  sprt<i<i  nim  in.<.coon.(.icM  nia.i.>.i..v.v...  ^ ^  ^^ 

the  middle  finger,  and  destroyed  a  portion  of  the  tip  of  the  index. 

To  face  p.  32.  Adlard  S-  Son,  Impr 


'^TROPHIC"    ULCERS  31 

the  needle  used  for  testing  sensibility  to  prick   can 
often  be  readily  seen  the  following  day. 

Changes  in  the  skin  of  a  similar  kind^  but  less 
marked,  occur  after  division  of  nerves  supplying 
other  parts  of  the  body. 

During  the  time  that  the  skin  is  insensitive  to 
protopathic  stimuli  it  is  peculiarly  liable  to  injury  ; 
a  burn  or  other  insult  is  unperceived,  and  in  this 
way  ulcers  may  be  produced  {vide  Plates  II  and  III), 
which,  from  their  situation  or  from  the  nature  of 
the  infection,  may  lead  to  the  destruction  of  a  con- 
siderable portion  of  the  affected  member.  In  many 
cases  the  patient  continues  his  work,  and  one  patient 
who  came  under  my  observation,  a  stonemason,  re- 
fusing to  trouble,  ground  away  the  terminal  phalanx 
of  his  fino'er  ao-ainst  the  stone  he  was  sawine'. 

"  Trophic  "  ulcers  usually  originate  in  blisters  ; 
if  ke23t  free  from  infection  these  dry  and  form  a 
callosity,  which  on  removal  leaves  a  raw  surface. 
The  blisters  are  produced  in  many  instances  by 
injuries  of  so  slight  a  nature  that  no  damage  results 
to  the  neighbouring  sound  skin  from  application  of 
the  same  violence.  For  example,  a  patient  travelling 
by  train  on  a  winter  day  felt  his  hand  cold;  when 
he  arrived  at  his  destination  he  found  blisters  on 
the  affected  fingers.  More  often  water  not  suffi- 
ciently hot  to  be  unpleasant  to  the  sound  portion  of 
the  hand  causes  blisters  on  the  affected ;  for  this 
reason  fomentations  must  be  employed  with   care  in 


32  INJURIES    OF    NERVES 

the  treatment  of  tliese  ulcers.  If  kept  at  rest  and 
free  from  irritation  they  heal  readily  and  do  not 
spread  beyond  the  analgesic  portion  of  the  limb 
unless  complicated  by  acute  sepsis. 

Blisters  may  originate  spontaneously ;  they  are 
often  noticed  on  waking  in  the  morning,  and  usually 
occur  at  a  time  when  sensibility  to  prick  is  beginning 
to  return  to  the  affected  portion  of  the  limb. 

The  appearance  of  the  fingers  and  hand  of  a 
patient  with  an  old  nerve  injury  is  usually  typical. 
The  fingers  are  thin  and  tapered  towards  their  points, 
with  wasting  of  the  subcutaneous  tissues,  particularly 
at  the  pulp  of  the  fingers.  The  skin  is  of  a  mottled 
reddish-blue  colour,  but  in  simple  non-irritative 
cases  never  becomes  so  red  and  shiny  as  to  merit 
the  term  "  glossy  skin  ^^ ;  this  must  be  reserved  for 
the  condition  to  which  it  was  originally  applied 
{vide  p.  42). 

Changes  in  nails. — It  has  been  known  for  many 
years  that  changes  in  the  nails  follow  nerve  injuries. 
The  nails  become  altered  in  texture,  are  harder  and 
more  brittle  and  lose  their  gloss.  They  also  become 
more  highly  curved  than  normal,  and  ribbed  in  both 
the  transverse  and  longitudinal  directions.  There  is 
often  a  heaping  up  of  epithelium  under  the  free 
edge  of  the  nail. 

The  rate  of  growth  of  the  nails  may  be  altered.  Dr. 
Head  and  the  author  showed  as  the  result  of  many 
observations  on  the  nails  of  the  fingers  of  sound  limbs. 


CHANGES   TN   NAILS,  HAIR,  BONES     33 

of  the  fingers  of  limbs  immobilised  for  the  treat- 
ment of  fractures,  and  as  the  result  of  paralysis 
due  to  central  causes,  as  well  as  in  nails  of  fingers 
insensitive  from  the  division  of  nerves  but  retaining 
the  power  of  voluntary  movement,  that  want  of 
movement  was  the  cause  of  the  diminished  growth  of 
the  nails  after  division  of  a  peripheral  nerve. 

When  the  skin  becomes  insensitive  as  the  result  of 
injury  to  a  nerve,  but  that  injury  has  not  divided 
tendons  or  paralysed  muscles,  the  nails  do  not  show 
any  change  in  growth.  The  most  profound  altera- 
tions in  growth  are  seen  after  division  of  the  ulnar 
nerve ;  here,  owing  to  the  paralysis  of  the  interossei 
muscles,  the  middle  and  index  finger-nails  are 
affected  as  well  as  the  little  and  ring. 

Changes  in  hair. — Changes  may  occur  in  the  hair 
as  the  result  of  nerve  injuries.  This  is  seen  most 
often  after  an  injury  dividing  the  nerves  of  the 
dorsum  of  the  hand.  The  hairs  appear  irregular, 
not  lying  in  regular  arrangement  as  seen  on  the 
normal  hand,  but  each  hair  occupying  a  different 
position.  They  may  show,  in  addition,  a  chauge  in 
colour  and  often  a  change  in  texture,  becoming 
brittle. 

Changes  in  bones  and  joints. — Acute  arthritis  fol- 
lowing a  nerve  injury  must  be  a  condition  of  rarit3\ 
I  have  not  yet  observed  it  in  any  of  the  cases  which 
have  come  under  my  notice. 

Changes  take   place   in  the  ligaments  and   joints 


34  m.JURIES    OF    NERYES 

retained  in  an  abnormal  position.  This  is  most 
often  seen  after  division  of  the  uhiar  nerve ;  the 
thick  anterior  ligament  of  the  interphalangeal  joints 
becomes  contracted  and  resists  full  extension.  At 
the  same  time  changes  may  occur  in  the  joint  itself ; 
occasionally  fibrous  ankylosis  takes  place,  but  such 
intra-articular  change  is  unusual. 

Changes  in  the  bones  must  also  be  uncommon.  I 
have  been  unable  to  find  evidence  of  textural  cliange 
in  recent  cases  by  palpation_,  the  occurrence  of  spon- 
taneous fracture  or  the  result  of  X-ray  examination. 
In  the  case  of  nerve  division  in  infancy,  for  example, 
widespread  birth  paralysis,  there  will  be  deficient 
growth  of  the  whole  limb  with  alteration  in  the 
shape  of  the  bones,  the  former  due  to  the  want  of 
movement,  the  latter  to  the  abnormal  position  of  the 
limb. 


CHAPTER    III 

Incomplete  Division  of  a  Peripheral  Nerve — Its  definition — 
Resulting  Loss  of  Sensibility;  of  Motion — Changes  in  Electrical 
Reactions — Cansalgia — Changes  in  Skin  and  Nails. 

Under  tlie  term  "  incomplete  division  "  are  grouped 
those  cases  of  interruption  or  impairment  of  con- 
ductivity which  do  not  lead  to  degeneration  of  the 
whole  peripheral  end  of  the  affected  nerve. 

This  incomplete  division  may  be  anatomical  or 
physiological_,  the  anatomical^  due  to  a  wound  or 
partial  rupture,  the  physiological,  the  result  of  com- 
pression of  the  nerve  by  fibrous  tissue,  extrinsic  or 
intrinsic,  by  bone,  blood-clot,  growth  or  external 
violence.  Although  the  treatment  and  prognosis  of 
the  different  forms  varies  somewhat  with  their  causa- 
tion, the  symptoms  are  identical,  and  for  this  reason 
it  is  well  to  discuss  them  together. 

It  has  been  found  on  examining  the  condition  of 
the  part  supplied  by  a  nerve  which  has  been  incom- 
pletely severed  by  a  sharp  cutting  instrument,  that 
a  considerable  portion,  certainly  a  third  of  the  trunk, 
may  be  divided  without  producing  motor  or  sensory 
change  or  one  of  a  transient  nature  only.  This  is 
most  important  in  connexion  with   the  operation  of 


36  INJUEIES    OF    NERYES 

nerve  anastomosis  (vide  p.  90).  In  this  operation 
it  is  essential  to  divide  nerve-fibres  in  a  sound  nerve 
in  order  that  the  axis  cylinders  in  the  affected  nerve 
may  be  brought  into  end-to-end  contact  with  some 
of  those  in  the  sound.  I  have  on  several  occasions 
divided  one  third  of  the  internal  popliteal  nerve 
without  producing  any  paralysis,  often  no  sensory 
change,  occasionally  a  loss  of  the  power  of  appreciat- 
ing light  touches  which  returned  in  a  few  days.  I 
have  also  done  the  same  to  the  hypoglossal  without 
producing  more  than  a  temporary  paresis  of  the 
muscles  supplied  by  it.  This  was  also  the  experience 
of  Bruandet  and  Humbert  as  the  result  of  their 
experiments  upon  animals.  They  came  to  the  con- 
clusion that  the  fibres  in  a  peripheral  nerve  which 
go  to  make  up  any  branch  do  not  become  grouped 
together  until  just  before  it  leaves  the  parent  trunk. 
But  there  are  exceptions  to  this  rule  ;  it  applies 
only  to  the  trunk  of  a  nerve  well  above  the  point  at 
which  branches  are  given  off  ;  if  the  incision  cuts 
into  the  nerve  just  above  the  ^^oii^t  of  origin  of  a 
branch  the  signs  of  complete  division  of  that  branch 
are  produced.  In  certain  situations  also — for  ex- 
ample, in  the  anterior  primary  division  of  the  fifth 
cervical  nerve — the  nerve-fibres  are  arranged  in  a 
well-defined  order,  and  incomplete  division  of  this 
nerve  may  entail  complete  division  of  those  motor 
fibres  which  supply  the  spinati  and  the  deltoid 
muscles  [vide  p.  199).      Again,  in  the   trunk   of  the 


INCOMPLETE    DIVISION  37 

great  sciatic  nerve^  the  external  and  internal  popli- 
teal ner\^es  remain  separate  from  tlieir  origin  in  the 
pelvis,  hence  incomplete  division  of  the  great  sciatic 
may  cause  complete  division  of  the  external  or 
internal  popliteal  nerve  (vide  p.  292). 

Bat  in  the  accidental  wounds  of  the  trunks  of 
nerves,  so  uncomplicated  a  section  is  rare ;  in  addi- 
tion to  the  incomplete  anatomical  division  there 
is  usually  physiological  division,  the  result  of  the 
transient  compression  of  the  intact  nerve-fibres  b}^ 
the  cutting  instrument  or  the  effused  blood.  It  must 
be  remembered  in  this  connexion  that  those  fibres 
which  are  separated  from  their  nerve  centres  must 
degenerate  and  regenerate  before  they  can  again 
carry  on  their  functions. 

Absence  of  symptoms  in  many  cases  is  due  to  the 
fact  that  more  nerve-fibres  are  present  in  the  trunk 
of  a  nerve  than  are  absolutely  necessary  to  sujjply 
the  part.  When  symptoms  are  present  the  recovery 
of  function  is  due  to  restoration  of  conduction  in  the 
fibres  which  have  suffered  an  incomplete  physiological 
division.  It  must,  however,  be  remembered  that  the 
injury  to  the  anatomically  intact  nerve-fibres  may  be 
so  great  that  complete  physiological  division  is  pro- 
duced ;  this  may  also  arise  at  a  later  ^leriod  as  the 
result  of  compression  by  fibrous  tissue. 

It  was  for  long  the  recognised  teaching  that  in- 
complete injuries  of  nerves  affected  the  motor  more 
than  tlie  sensory  fibres.        I   showed,  in  my  Erasmus 


38  INJURIES    OF    NERVES 

Wilson  Lectures^  tliat  tliis  was  not  the  case.  Out  of 
nineteen  instances  of  incomplete  division  of  mixed 
nerveS;  from  various  causes  (excluding  tlie  musculo- 
spiral)^  seen  at  that  date_,  sensibility  was  affected  in 
all ;  in  six  there  was  no  paralysis^  and  in  one  it  did 
not  affect  all  the  muscles  supplied  by  the  injured 
nerve  below  the  lesion.  Since  that  date  I  have  been 
able  to  confirm  this  by  many  more  observations. 
Motion  is  ajffected  alone  or  to  a  greater  extent  than 
sensation  only  when  the  injury  affects  nerves  such 
as  the  musculo-spiral  or  the  fifth  cervical  anterior 
primary  division,  which  have  no  exclusive  sensory 
^^PPb%  ^^^  whose  complete  division  has  no  demon- 
strable effect  upon  sensation. 

Sensory  symptoms. — The  first  effect  of  incom- 
plete division  of  a  mixed  nerve  is  upon  epicritic 
sensibility.  In  many  slight  cases  there  is  no  area 
of  loss  of  sensibility  that  can  be  marked  out  by 
stimulation  with  cotton-wool ;  this  can  be  appre- 
ciated everywhere  and  minor  degrees  of  temperature 
discriminated.  But  the  patient  is  conscious  of 
an  area  of  skin  altered  in  sensibility,  and  it 
is  usually  possible  to  demonstrate  this  by  the 
changed  sensibility  produced  at  its  borders  when  a 
piece  of  cotton-wool  or  a  sharp  point  is  dragged 
lightly  across  the  skin  from  sound  to  affected  por- 
tions (line  of  change).  If  the  area  of  changed 
sensibility  is  well  marked  response  to  the  compass 
test  will  be  defective. 


SENSORY    SYMPTOMS  39 

But  in  those  cases  which  come  under  the  care  of 
the  surgeon,  loss  of  sensibility  to  cotton-wool  is 
usually  absolute,  with  borders  as  well-defined  as 
after  complete  division.  Complete  loss  of  epicritic 
sensibility  may  be  the  only  sign  of  the  injury,  motion 
may  be  entirely  unaffected.  The  following  is  a  good 
example  of  this  tyj^e  of  injury  : 

"  A  boy,  aged  thirteen,  was  strapped  by  Sayre's 
method  for  a  fractured  clavicle.  When  the  limb 
was  taken  down  he  complained  of  numbness.  On 
examination  I  found  loss  of  sensibility  to  light  touch 
over  the  ulnar  area,  with  no  affection  of  the  muscles- 
Yet  it  was  five  months  before  complete  recovery 
ensued  with  perfect  discrimination  of  two  ^Doints.^^ 

When  the  injury  is  more  severe,  impairment  or 
loss  of  protopathic  sensibility  results  and  the  sensory 
loss  may  resemble  exactly  that  seen  after  complete 
division.      The  following  is  illustrative  of  this. 

"  C.  B — ,  aged  twenty-seven  years,  slipped  and  cut 
his  wrist  with  a  broken  bottle.  He  came  to  the  London 
Hospital  at  once  and  was  seen  by  me  an  hour  and  a 
half  after  the  accident.  An  oblique  wound  was 
present  on  the  anterior  surface  of  the  wrist,  running 
from  the  tendon  of  the  flexor  carpi  radialis  upwards 
and  outwards  for  au  inch  and  a  half. 

"  The  opponens  and  abductor  pollicis  muscles  acted 
well.  He  was  unable  to  appreciate  light  touch  over 
the  full  median  area ;  sensibility  to  prick  was 
abolished  over  the  terminal  two  phalanges  of  index 


40  INJUEIES    OF    NERVES 

and  middle  fingers  and  an  area  on  tlie  palm  at  tlieir 
base. 

"  I  explored  the  wonnd  at  once  and  fonnd  the 
median  nerve  swollen  with  a  small  incised  wound  on 
its  ulnar  side/^ 

In  this  patient  the  loss  of  epicritic  and  proto- 
pathic  sensibility  was  as  widespread  and  of  as 
profound  a  degree  as  after  complete  division  of 
the  nervO;  yet  there  was  no  motor  affection.  As  a 
rule^  however^  when  sensibility  is  impaired  to  this 
degree  voluntary  power  is  also  affected. 

Motor  symptoms. — Paralysis  of  some  or  all  of  the 
muscles  supplied  by  the  injured  nerve  may  result 
from  incomplete  division.  It  is  only  after  sufficient 
time  (eight  to  fourteen  days)  has  elapsed^  to  allow  of 
the  development  of  electrical  changes^  that  the 
diagnosis  of  incomplete  division  can  be  made  in 
many  instances. 

In  the  least  severe  cases  the  muscles,  thouo-h 
paralysed_,  retain  their  irritability  to  the  interrupted 
current ;  this  is  seen  most  often  in  crutch  and  sleep 
paralyses  ;  rarely — though  two  such  cases  have  come 
under  my  care — the  muscles  retain  the  ^^ower  of 
voluntary  movement^  but  do  not  respond  to  stimu- 
lation with  the  interrupted  current.  Usually  the 
reactions  that  I  consider  typical  of  incomplete 
division  arc  present.  On  about  the  tenth  da}^  after 
the  injury  the  muscles  do  not  respond  to  the  inter- 
rupted current;  but  react  in  a  characteristic  manner 


MOTOR    SYMPTOMS  41 

when  stimulated  with  the  constant.  The  strength 
of  current  necessary  to  call  forth  the  contraction  is 
less  than  on  the  sound  side ;  the  contraction  so 
produced  is  brisk  as  compared  with  that  seen  when 
the  reaction  of  degeneration  is  present,  and  polar 
reversal  is,  as  a  rule,  absent. 

When  I  delivered  the  Erasmus  Wilson  Lectures 
in  1906,  I  had  been  able  to  investigate  nineteen  cases 
of  incomplete  division  of  nerves  associated  with 
paralysis,  and  in  eighteen  of  these  this  reaction  was 
present ;  in  the  other  patient  the  muscles  reacted  to 
the  interrupted  current.  Since  that  date  I  have  had 
the  ojDportunity  of  investigating  further  cases  of  this 
description ;  in  all — some  of  them  patients  sent  for 
operation — the  diagnosis  made  by  electrical  examina- 
tion was  confirmed  by  the  after-history  of  the  case. 

After-results  of  incomplete  division. — Pain  is  a  more 
frequent  symptom  after  both  anatomical  and  physio- 
logical incomplete  division  than  after  complete 
division,  and  is  often  accompanied  by  tenderness  of 
the  skin  (hyperalgesia),  sometimes  by  glossy  skin  and 
chano'es  in  the  QTowtli  of  the  nails. 

O  a 

These  symptoms  only  occur  as  the  result  of  irrita- 
tion ;  they  rarely  arise  immediately,  a  latent  j^eriod  of 
a  few  days  to  three  weeks  usually  being  present.  The 
pain  is  most  severe  when  there  has  been  an  incom- 
plete anatomical  division,  and  is  most  often  seen  after 
gunshot  wounds.  The  first  case  of  this  nature  was 
reported    by   Doiniuirk  in    ISlo  ;    the    patient  was   a 


42  INJURIES    OF    NERVES 

soldier  wounded  at  tlie  storming  of  Badajoz.  Later^ 
Paget  drew  attention  to  this  symptom  in  injuries  in 
civil  life^  and  liis  words  well  describe  tlie  condition 
and  tlie  knowledge  tliat  was  then  possessed  with 
regard  to  it.  "  Glossy  fingers  appear  to  be  a  sign 
of  peculiarly  impaired  nutrition  and  circulation  due 
to  the  injury  of  nerves.  They  are  not  observed  in 
all  cases  of  injured  nerves_,  and  I  cannot  tell  what 
are  the  peculiar  conditions  of  the  cases  in  Avhicli  they 
are  found^  but  they  are  a  very  notable  sign  and  are 
always  associated_,  I  think^  with  distressing  pain  and 
disabilityc  In  well-marked  cases  the  fingers  which 
are  affected  are  usually  tapering,  smooth_,  hairless, 
almost  devoid  of  wrinkles,  glossy,  pink,  or  ruddy,  or 
blotched  as  if  with  j^ermanent  chilblains.  They  are 
commonly  also  painful,  especially  on  motion,  and  the 
pain  often  extends  from  them  up  the  arm.^^  The 
cases  upon  which  this  description  was  based  were 
instances  of  incomplete  physiological  division. 

But  it  is  to  Weir  Mitchell,  Morehouse  and  Keen 
that  we  owe  the  first  complete  description  of  this 
condition  named  by  them  "  causalgia,"  based  upon 
their  observations  of  the  results  of  gunshot  wounds 
of  nerves  during  the  American  Civil  War.  The 
following  description  from  Weir  Mitchell^s  book 
describes  the  condition  with  accuracy :  "^  The  skin 
affected  in  these  cases  was  deep  red  or  mottled,  or 
red  and  pale  in  patches.  The  subcuticular  tissues 
were  nearly  all  shruukeu,  and  where  the  palm  alone 


CAUSALGIA  43 

was  attacked  tlie  part  so  diseased  seemed  to  be  a 
little  depressed  and  firmer  and  less  elastic  than 
common.  In  the  fingers  there  Avere  often  cracks  in 
the  altered  skin^  and  the  integuments  presented  the 
appearance  of  being  tightly  drawn  over  the  sub- 
jacent tissues.  The  surface  of  all  the  affected  parts 
was  glossy  and  shining^  as  though  it  had  been  skil- 
fully varnished.  Nothing  more  curious  than  these 
red  and  shining  tissues  can  be  conceived  of.  In 
most  of  them  the  part  was  devoid  of  Avrinkles  and 
perfectly  free  from  hair.  Mr.  Paget^s  comj^arison 
of  chilblains  is  one  we  often  used  to  describe  these 
appearances^  but  in  some  instances  we  have  been 
more  strikingly  reminded  of  the  characters  of  certain 
large^  thin,  and  polished  scars. ^^ 

Butj  as  seen  in  civil  life^  the  condition  is  rarely  so 
severe ;  it  may  result  from  penetrating  wounds, 
primary  injury  in  association  with  fractures,  or  a 
direct  blow.  After  a  latent  period  of  a  few  days 
intense  burning  pain  makes  its  appearance.  The 
painful  area  is  usually  extremely  tender  and  maps 
out  the  full  distribution  of  the  injured  nerve,  and 
may  present  the  skin  changes  described  above,  but 
these  are  by  no  means  constant  and  only  present  in 
the  most  severe  cases. 

Loss  of  sensibility  may  be  present,  varying  accord- 
ing to  the  nerve  injured  and  the  degree  of  that 
injury ;  usually  the  loss  is  of  epicritic  sensibility  only. 
The  pain  soon  affects  the  patient^s  general  conditicni. 


44  INJURIES    OF    NERVES 

lie  rapidly  loses  self-control  and  becomes  ^^  hysterical/^ 
often  bursting  into  tears  on  the  suggestion  of  a  local 
examination. 

On  exploration  the  nerve  is  found  locally  enlarged 
and  often  embedded  in  fibrous  tissue.  The  condition 
may  perhaps  be  considered  as  a  neuritis  ;  it  occurs 
most  often  in  gunshot  wounds  with  delayed  union, 
but  in  several  cases  Avhich  have  come  under  my  care 
the  wounds  healed  by  first  intention_,  and  it  may  occur 
as  the  complication  of  a  subcutaneous  injury  {vide 
also  p.  134). 

The  skin  changes  are  different  to  those  seen  after 
complete  division.  The  skin  sweats  profusely  and  the 
affected  area  may  often  be  marked  out  by  beads  of 
moisture.  In  some  cases  the  subcutaneous  tissues 
appear  to  be  increased  in  size_,  and  the  nails  may 
become  more  curved  and  grow  faster  than  those  of 
the  unaffected  hand.  Blisters  may  make  their 
appearance  and  break  down  to  form  ulcers ;  these 
may  appear  not  only  over  the  area  of  sensory  loss_, 
but  often  over  the  area  in  which  there  is  hyperalgesia 
but  no  loss  of  sensibilitv. 

In  cases  of  incomplete  division  without  irritation 
the  changes  in  the  skin  are  little  marked  unless 
the  injury  has  resulted  in  protojoathic  loss_,  when 
they  may  resemble  those  seen  after  complete 
division.  As_,  after  complete  division_,  the  changes 
in  the  nails  will  depend  upon  the  extent  of  the  loss 
of  movement  resulting  from  the  injury. 


CHAPTER    IV 

Method  of  Examination  and  Diagnosis— History— Examination  of 
the  Patient— Method  of  Testing  Sensation— Electrical  Exa- 
mination— Diagnosis  :  in  recent  cases  ;  in  old  cases. 

It  is  necessary  to  follow  some  definite  plan  in  tlie 
examination  of  a  case  of  nerve  injury  or  points  are 
omitted  wliicli  are  essential  to  full  diagnosis.  The 
full  diagnosis  consists  in  the  discovery  of  the  nerve 
or  nerves  injured,  the  anatomical  position  of  the 
iujury  and  its  nature,,  whether  complete  or  incomplete. 

Before  commencing  the  local  examination  the 
history  should  be  taken ;  much  light  is  often  thrown 
on  obscure  cases  by  listening  carefull}^  to  the 
patient^s  account  of  the  accident  and  his  subsequent 
experiences.  The  important  points  to  be  elicited 
are,  the  date  of  the  accident,  and,  as  far  as  possible, 
its  exact  nature  ;  then,  what  symptoms  pointing  to 
a  nerve  injury  first  attracted  the  attention  of  the 
patient,  and  the  time  after  the  accident  at  which 
such  sensory  change,  paresis  or  paralysis,  was 
noticed. 

In  old  cases  inquiry  should  be  made  for  increase 


46  IXJUEIES    OF    NERVES 

or  diminution  in  the  extent  or  degree  of  the  sensory 
or  motor  symptoms.  If  j)ain  has  been  present  at 
any  time^  questions  must  be  put  to  ascertain  the 
date  of  its  onsets  its  exact  distribution  and  character, 
whether  neuralgic,  burning,  etc.,  if  it  varies  in 
severity  from  time  to  time,  if  it  has  spread  to  areas 
other  than  that  first  affected,  or  the  patient  is  aware 
of  anything  that  increases  it  or  can  obtain  relief 
from  it  in  any  way.  Some  idea  must  be  formed  of 
its  severity,  whether  keeping  the  patient  awake  at 
night,  or  affecting  his  mental  condition  or  general 
health.  If  the  nerve  was  injured  in  a  wound,  how 
long  the  wound  took  to  heal,  and  the  nature  of  its 
treatment. 

It  is  useful  to  conduct  the  routine  examination 
under  the  following  three  headings :  (1)  Greneral 
inspection  of  the  part  injured ;  (2)  examination  of 
sensation ;   (3)  examination  of  muscles. 

1.  General  inspection  of  the  part  injured : 
{a)  Position  of  injured  ]3art  or  limb. 
(h)    Wounds,  scars,  etc. 

(e)  Condition  of  skin — changes  in  colour,  des- 
quamation, blisters,  ulcers,  alterations  in 
temperature. 

(d)    Condition  of  nails  and  hair. 

2.  Examination  of  sensation  : 
(a)   For  tenderness. 

(h)  For  loss  of  epicritic,  protopathic,  and  deep 
sensibility. 


METHOD    OF    EXAMINATION  47 

3.  Muscular  examination : 

{a)   Wasting,  general  and  localised,  contractures. 

(h)    Paralj^sis. 

(c)  Electrical  changes. 
1.  (a)  The  position  taken  np  b}^  the  injured 
limb  or  part  may  at  once  reveal  the  nerve  involved ; 
the  drop  wrist  of  musculo-spiral  injury,  the  drop  foot 
of  injury  to  the  external  popliteal,  the  ulnar  hand 
and  the  true  claw  hand  of  injury  to  the  median  and 
ulnar  are  examples. 

(b)  The  presence  of  wounds  and  of  scars  must  be 
noted,  their  nature  and  anatomical  position.  If  a 
scar,  whether  showing  signs  of  ]3rimary  union  or  of 
healing  by  granulations,  whether  free  of  the  deep 
tissues,  or,  if  adherent,  to  what  structures  ?  Palpa- 
tion in  the  neighbourhood  may  reveal  the  presence 
of  bulbous  enlargements,  or  of  tenderness  accom- 
panied by  pain  referred  to  the  affected  limb. 

(c)  The  condition  of  the  skin  should  alwaj^s  be 
investigated  ;  the  desquamating  skin  seen  a  few  days 
after  the  injury,  the  dry,  bluish  pink,  atrophic  skin  of 
a  later  period  or  the  red  glossy  skin,  often  covered 
with  beads  of  perspiration  will  all  aid  in  diagnosis. 
When  blisters  are  present,  their  exact  situation  and 
relation  to  the  area  of  analgesia,  or  of  epicritic  loss. 
A  note  should  be  made  as  to  the  mode  of  onset  of 
the  blisters  or  ulcers,  if  they  originated  in  response 
to  injury  or  appeared  spontaneously.  If  the  latter, 
this  may  point  to  commencing  recovery. 


48  INJURIES    OF    NERVES 

(d)  The  nails  should  be  examined  for  changes  in 
colour  or  gloss^  for  brittleness^  growth  of  epithelium 
under  the  free  edge^  curvature,  ridging,  etc. 

2.  In  testing  sensation,  quiet  surroundings  are 
essential.  The  patient  should  be  comfortably  seated 
with  the  aifected  part  resting  easily,  so  that  no 
restraint  is  imposed  or  muscular  effort  necessar}^  to 
maintain  the  position  of  the  limb.  The  eyes  of  the 
patient  should  be  closed,  if  necessar}^,  bandaged. 
He  should  be  told  to  speak  whenever  he  feels  any- 
thing, whether  a  prick,  a  touch,  or  any  other  sensa- 
tion or  change  in  sensation.  No  further  questions 
should  be  asked.  The  usual  method  of  testing, 
touching  or  pricking  the  patient  and  saying,  "  do  you 
feel  this,  etc.,^^  is  more  time-consuming  and  quite 
untrustworthy. 

{a)  If  pain  is  complained  of  or  the  condition  of 
the  part  is  suggestive,  the  examination  should  be 
first  conducted  to  find  out  if  tenderness  of  the  skin 
is  present  and  its  exact  extent  marked  out.  This 
can  be  done  by  dragging  the  point  of  a  pin  lightly 
across  the  limb  from  the  sound  to  the  affected  side, 
the  patient  being  told  to  speak  as  soon  as  the 
stimulus  becomes  painful.  Immediately  the  tender 
area  is  reached,  the  patient  withdraws  the  hand  and 
shows  obvious  signs  of  discomfort. 

(h)  Epicritic  sensibility  should  be  tested  first;  it 
is  the  system  first  affected  in  any  injury  of  peripheral 
nerves,    and  the   extent  of    its  loss  is  greater  than 


TESTS    FOR    LIGHT    TOUCH  49 

that  of  prick  or  deep  touch.  By  this  form  of  sensi- 
bility light  touches  are  appreciated^  temperatures 
between  about  22°  C.  and  38  C.  discriminated^  and 
localisation  as  tested  by  the  compasses^,  rendered 
possible. 

For    routine    clinical  work    the    testing    of    light 
touch  is  usually  sufficient^  but  temperature  tests  and 
the  compass  test  are  valuable  in  cases  of  difficulty  or 
doubt.      Light  touch  is  tested  by  means  of    cotton- 
wool rolled  up  to  form  a  pledget,  or  a  soft  cameFs 
hair    brush    stroked  gently  over    the    affected  part. 
This    test    must    be     applied    with     circumspection. 
Certain    parts — for  example,  the    outer  part  of  the 
thenar  eminence  —  even  of    a  well-kept    hand,    are 
relatively  insensitive    to    cotton-wool   and    over  the 
greater  part    of    the  palm  of    a    working    man    no 
response  may  be  obtained.      Again,  if  used  roughly, 
or    dabbed  on  at  right-angles  to  the   surface,  deep 
touch  may  be  evoked  ;   even  when  lightly  employed 
over     desquamating    areas    this     stimulus    may    be 
appreciated    by    means  of  deep  sensibility.      Errors 
may   also    arise    with  this   form  of  stimulation  over 
hair-clad  parts  in  which  there  is  retention  or  return 
of  sensibility  to  prick.      This  is  particularly  liable  to 
happen  over  the   dorsum  of    the    hand    or   external 
popliteal   area  of   the    leg,   and  may   lead   to  errors 
in   diagnosis   or  to   over-estimation  of   the   stage  of 
recovery.      But  the  sensation  produced  by  the  cotton- 
wool  in  these   cases  is    entirely  different,  from  that 

4 


50  INJUEIES    OF    NERVES 

given  b}^  stimulation  of  tlie  liairs  on  a  normal  part 
of  the  limb  witli  cotton-wool ;  it  possesses  the  radiat- 
ing, tingling  character  associated  with  protopathic 
sensibilit}^  On  shaving  a  part  in  this  condition  it 
becomes  entirely  insensitive  to  cotton-wool.  In  all 
cases  of  doubt  this  should  be  done  and  the  tempera- 
ture and  compass  tests  applied. 

It  sometimes  happens  that  epicritic  sensibility  is 
altered  but  not  abolished.  In  these  instances  the 
patient  is  often  able  to  define  an  area  of  skin  within 
which  sensation  is  altered;  dragging  a  piece  of 
cotton-wool  across  the  part  from  sound  to  affected 
portions  will  also  mark  it  out_,  and  the  compass  test 
is  in  most  cases  defective. 

Within  the  area  of  epicritic  loss,  but  retained 
protopathic  sensibility  (intermediate  zone)_,  a  prick 
and  the  more  extreme  degrees  of  temperature  are 
appreciated,  but  the  patient  entirely  fails  to  discri- 
minate water' at  about  22°  C.  from  water  at  about  38° 
C,  and  sensibility  to   the  compass  test  is  defective. 

Glass  test-tubes  containing  ice  and  water  at  50°  C. 
are  used  for  investigating  the  extreme  degrees  of 
temperature  ;  for  the  minor  degrees  similar  tubes 
containing  water  at  about  24°  C.  and  38°  C.  These 
temperatures  should  be  readily  discriminated  by  the 
patient  as  cool  and  warm  over  the  corresponding 
sound  part,  and  should  be  first  employed  there  and 
not  used  as  tests  for  epicritic  sensibility  unless  the 
patient    is    able    readily    to    distinguish    them    over 


COMPASS    TEST  51 

normal  parts.  So  many  difficulties  surround  tlie 
testing  of  the  minor  degrees  of  temperature  that  too 
much  reliance  should  not  be  placed  on  failure  to  dis- 
criminatCj  and  the  test  should  only  be  used  in  cases 
of  difficulty. 

In  applying  the  compass  test  the  blunt  points  of  a 
pair  of  compasses  are  separated  from  one  another  for 
a  measured  distance.  The  skin  of  the  affected  por- 
tion of  the  limb  is  touched_,  and  the  patient  is  asked 
to  say  after  each  stimulation  whether  he  has  been 
touched  by  one  or  two  points.  When  they  are 
separated  for  less  than  a  certain  distance^  varying 
with  the  part  of  the  body  under  examination^  the 
points  no  longer  appear  as  two  on  the  normal  skin. 
Dr.  Head  and  the  author  found  that  two  points 
could  be  accurately  recognised  over  any  part  of  the 
normal  palm  when  separated  for  1  cm.  and  applied 
transversely.  This  is  more  convenient  than  longi- 
tudinal application^  for  the  area  available  for  testing 
is  limited  and  the  points  are  appreciated  at  a 
smaller  distance  apart  when  applied  in  this  manner. 
In  carrying  out  the  test  the  method  introduced  by 
us  is  useful.  The  patient  is  touched  ten  times  with 
one  pointy  ten  times  with  two^  each  being  applied  at 
random.  The  results  are  recorded  graphically  in 
the  following  manner.  Every  time  the  patient^s 
answer  is  correct  a  stroke  is  made,  above  a  hori- 
zontal line  if  he  was  touched  with  one  point,  below 
if  he  was  touched  with   two.       An  incorrect  answer 


52  INJURIES    OF    NERVES 

is  recorded  by  a  cross.  Thus,  if  lie  answers  one 
when  toiiclied  with  two  points  a  cross  is  placed 
below  the  line.  A  preceding  stimulus  frequently 
has  an  effect  upon  those  Avhich  follow  it,  and  to 
register  the  order  in  which  the  stimuli  have  been 
applied  is  therefore  an  additional  aid  to  the  inter- 
pretation of  the  records.  Thus^  if  the  testing  began 
with  four  double  touches  correctly  answered  four 
strokes  would  be  made  below  the  line.  At  the 
point  above  the  line  directly  over  the  last  of  these 
would  begin  the  record  of  the  subsequent  single 
stimuli  j  in  this  way  the  results  of  all  further  stimuli 
are  recorded  until  the  number  is  complete. 

Perfect  appreciation  of  the  compass  points  at  a 
distance  of  2  cm.  would  be  represented  thus  : 

1  I  I  I        II       I  I  I  II 

2  cm.  ^ 

2  II  i  I    i  II  III 

If,  however,  the  patient  is  unable  to  differentiate 

the  two  points   at   this   distance,   answering    one   to 

every  stimulation,  the  record  would  stand  : 

1         I  I  I  I  I  I   I  I  I  I 

2  cm.  „   

2XX  XXXX  XXXX 

Such    a    formula    would  show    that    when    2  cm. 

apart  the  sensation  produced  by  two  points  is  well 

below  the  threshold  at  which  discrimination  becomes 

possible.      Less  complete  failure  would  be  represented 

by  some  such  formula  as — 

1   IIXX    IX      IXXI 


2  cm. 


2  XI     IX         IIXXX 


TESTS  FOE  PROTOPATHIC  SENSIBILITY  53 

where  50  per  cent,  of  the  answers  are  wrong  with 
one  pointy  60  per  cent,  with  two  j^oiiits.  A  curious 
phenomenon  is  the  tendency  to  appreciate  one  point 
as  two  as  soon  as  the  limits  of  accurate  discrimina- 
tion are  passed. 

Used  in  this  manner  the  test  becomes  a  valuable 
one. 

A  sharp  needle  or  pin  should  be  used  as  the 
test  for  pain^  and  care  must  be  taken  that  the 
patient  understands  he  is  only  to  speak  when  he 
feels  the  ]iain  of  the  prick^  not  when  he  feels 
pressure  or  a  touch.  Unless  this  precaution  is  taken 
mistakes  easily  occur^  particularly  after  division  of 
the  median  or  external  popliteal  nerves^  when  large 
areas  are  often  present  sensitive  to  pressure  but 
insensitive  to  prick.  If  any  doubt  exists  it  is  easy 
to  discover  if  sensibility  to  pain  is  present  by  using 
a  painful  interrupted  current.  When  the  iron  core 
is  inserted  into  the  primary  circuit  of  an  induction 
coil,  the  current  possesses  a  painful  character  due_,  as 
suggested  by  Dr.  Lewis  Jones  and  confirmed  by  Dr. 
Head,  to  the  greater  duration  of  the  current  waves. 
This  painful  stimulation  is  not  appreciated  over  the 
area  where  deep  sensibility  is  present  but  protopathic 
sensibility  is  lost. 

No  temperature  sensations  can  be  evoked  from  an 
area  within  which  cutaneous  sensibility  is  absent. 
For  testing,  tubes  containing  ice  and  water  at  50°  C. 
should  be   used,  and   the  patient  asked  to  state  the 


54  INJURIES    OF    XERYES 

nature  of  the  stimulation^  whether  a  tonch^  warm  or 
cold. 

Deep  sensibility  may  be  tested  by  means  of  the 
pressure  of  a  pencil  or  other  blunt  object ;  no  diifer- 
ence  in  size  can  be  perceived  between  the  point  of 
a  pin  and  the  blunt  end  of  a  pencil.  One  patient 
was  unable  to  recognise  the  difference  between  the 
point  of  a  pin  and  the  end  of  a  cylindrical  rod  2  cm. 
in  diameter;  both  appeared  to  be  pressure.  The 
appreciation  of  size  (acuaesthesia)  is  a  property  of 
epicritic  sensibility. 

It  must  be  remembered  that  when  deep  sensibilit}' 
is  present,  pain  may  be  produced  if  the  pressure  is 
excessive  and  corresponds  to  the  amount  necessary 
on  the  sound  side  to  produce  pain.  This  can  be 
measured  by  Rivers'  modification  of  CattelFs  algo- 
meter.  To  call  forth  the  pain  of  deep  pressure  a 
blunt  object  must  be  employed;  it  is  impossible  to 
call  it  forth  by  means  of  the  pin  or  needle  used  in 
testing,  a  pressure  of  from  2  to  4  kgms.  being 
necessary. 

In  testing  the  sense  of  passive  position  and  move- 
ment, the  patient,  whose  eyes  are  closed,  is  asked  to 
imitate  with  the  corresponding  sound  part  the  move- 
ment of  the  part  under  examination.  For  instance, 
in  testing  the  sense  of  passive  movement  and  position 
in  the  first  interphalangeal  joint  of  a  finger,  the 
second  phalanx  is  held  between  the  observer's  finger 
and    thumb    and   moved   in   various    directions,   the 


EXAMINATIOX    OF    MUSCLES  55 

patient  imitating  this  with  the   corresponding  finger 
of  the  sound  hand. 

3.  The  method  of  examination  of  the  affected 
muscles  is  important^  and  mistakes  often  occur  from 
incompleteness  of  examination. 

(a)  The  distribution  and  amount  of  wasting  and 
the  presence  and  degree  of  contracture  of  the  opposing 
muscles  should  be  noted. 

(b)  I  have  already  pointed  out  the  care  which  is 
necessary  in  this  examination  to  avoid  overlooking 
the  paralysis  of  individual  muscles. 

(c)  It  is  most  important  that  this  should  he 
thoroughly  understood^  and  it  should  be  carried  out, 
if  possible,  by  the  surgeon  who  will  be  responsible 
for  the  treatment  of  the  case.  The  reactions  of  the 
muscles  to  both  constant  and  interrupted  currents 
must  be  investigated  in  most  cases.  A  battery  in 
which  both  currents  are  combined,  the  constant  with 
a  galvanometer  in  the  circuit  is  most  serviceable. 
It  is  so  constructed  that  with  the  electrodes  attached 
to  one  pair  of  terminals,  either  the  interrupted  or 
the  constant  current  maj^  be  used,  and  the  latter 
reversed.  Where  electric  light  is  installed  the 
current  may  be  taken  from  the  main  and  its  voltage 
reduced."^ 

The    testing    electrode  should  be   of    the  closing 

type,  that  is,  the  current  should  not  pass  through  it 
*  For  information  on  this  and  on  the  theoretical  side  of  muscles 
testing  the  reader  is  referred  to  Dr.  Lewis  Jones'  book  on  Medical 
Electricity. 


56  INJURIES    OF    NERVES 

until  the  kej  is  depressed  ;  it  should  have  a  small 
bulbous  end  covered  with  wash-leather.  The  best 
form  of  indifferent  electrode  is  the  padded  metal 
plate.  The  indifferent  electrode  is  attached  to  the 
terminal  marked  +,  the  testing  one  to  that  marked  — . 

The  testing  electrode  is  to  be  applied  to  the 
muscles  at  or  near  their  motor  ^^oints.  These  are 
situated  at  or  near  the  point  of  entry  of  the  motor 
nerves  ;  they  vary  slightly  in  different  individuals, 
but  their  general  situation  is  the  same  and  should  be 
learnt  by  practical  muscle  testing.  The  indifferent 
electrode  should  be  firmly  placed  against  some 
remote  part  of  the  body,  where  the  muscular  con- 
tractions which  may  be  ^Droduced  will  not  interfere 
with  the  examination  of  the  affected  part.  When  the 
legs  are  being  tested,  it  may  be  placed  in  a  basin  of 
normal  saline  which  immerses  the  patient's  opposite 
hand,  but  this  position  interferes  with  the  testing 
of  the  upper  limb.  In  testing  the  intrinsic  muscles 
of  the  hand  the  best  results  are  obtained  when  the 
indifferent  electrode  is  placed  on  the  opposite  side  of 
the  hand  to  that  under  investigation. 

Both  the  electrodes  and  the  parts  to  be  examined, 
not  omitting  the  corresponding  sound  limb,  must  be 
well  soaked  in  warm  normal  saline  solution  before 
commencing  to  test. 

Begin  testing  with  the  interrupted  current,  using  a 
strength  of  current  just  sufficient  to  contract  the 
muscles  of  the  observer's  thenar  eminence.      Always 


ELECTRICAL    REACTIONS  57 

use  the  current  from  the  secondary  coil  (see  that  the 
switch  is  on  S) — that  from  the  primary  is  more 
painfuL 

A  good  light  is  essential  in  order  to  see  that  the 
muscle  under  observation  contracts  ;  in  some  cases 
palpation  over  its  tendon  of  insertion  is  necessary. 
If  the  muscles  under  examination  react  to  the  inter- 
rupted current  no  further  investigation  is  necessary. 

If  they  do  not  react  to  this  form  of  stimulation 
they  must  be  tested  with  the  constant  current. 
Their  reactions  to  this  form  of  excitation  are  most 
important^  for  in  many  cases  Ave  have  to  reh^  upon 
the  nature  of  their  response  for  the  diagnosis  be- 
tween complete  and  incomplete  division. 

A  normal  muscle  responds  to  stimulation  with  the 
constant  current  with  a  brisk  twitch  when  the  test- 
ing electrode  is  negative  and  the  current  is  closed 
(K.C.C.).  Li  examining,  apply  the  testing  electrode 
to  the  muscle  and  close  the  current  by  depressing  the 
key  in  the  handle  of  the  electrode,  and  observe  on 
the  galvanometer  the  current  necessary  to  produce  a 
response,  then  reverse  the  current,  causing  the  test- 
ing electrode  to  become  positive  (A.C.C.),  and  again 
note  the  strength  of  current  necessary  under  these 
conditions.  In  all  cases  compare  the  response  given 
by  the  affected  muscles  and  the  current  necessary  to 
produce  it  with  that  given  by  the  corresponding  mus- 
cles of  the  sound  side ;  this  must  never  bo  omitted. 

In  children  a  general  ana3sthetic  is  often  necessary. 


58  m.JUEIES    OF    XERYES 

Examination  in  cases  of  recent  injury. — In  recent 
cases  the  scheme  of  examination  must  be  somewhat 
modified.  Tlie  complete  diagnosis  cannot  be  made, 
apart  from  exploration,  until  such  time  has  elapsed 
as  will  suffice  for  the  development  of  electrical  changes 
in  the  aifected  muscles.  But  in  a  laro-e  number  of 
the  cases  that  are  seen  soon  after  the  accident,  the 
nerve  is  injured  as  the  result  of  an  incised  wound  in 
the  region  of  the  wrist,  and  it  cannot  be  too  strongly 
insisted  upon  that  a  thorough  examination  of  the 
parts  below  the  wound  should  be  carried  out  on  the 
lines  laid  down,  before  any  attempt  is  made  to  deal 
with  the  wound  or  divided  structures  under  an 
aneesthetic.  ISTumerous  instances  have  come  under 
the  writer's  notice  in  Avhich  nerve  injuries  haA^e  been 
overlooked  for  want  of  obeying  this  simple  rule. 
Before  starting  a  lengthy  operation  upon  recently 
divided  nerves  and  tendons  it  is  well  to  know  what 
structures  are  divided,  and  not  to  trust  to  a  chance 
discovery  to  enable  the  correct  structures  to  be  found 
and  sutured. 

Similarly  all  cases  of  fractures  and  dislocations  or 
falls  on  the  shoulder  should  be  examined  for  signs 
of  nerve  injury  before  being  treated.  An  instruc- 
tive case  of  this  nature  recently  came  under  my 
notice.  A  patient  sustained  a  dislocation  of  the 
shoulder,  which  was  treated  at  a  hospital  and  the 
dislocation  reduced;  he  obtained  compensation  for 
this   injury.        Some   time   later    he  was    dissatisfied 


EXAMINATION    AND    DIAGNOSIS        59 

with  the  use  of  his  arm  and  came  under  my  care.  I 
found  a  partial  rupture  of  the  fifth  cervical  anterior 
primary  division^  upon  Avhich  I  operated.  The 
patient,  considering  that  he  had  received  compensa- 
tion for  the  dislocation  only^  then  claimed  a  further 
sum,  and  was  successful  in  obtaining  in  Court  a  con- 
siderable sum  in  addition  to  what  he  had  at  first 
received. 

In  the  usual  glass-cut  wounds  in  the  region  of  the 
wrist,  tendons  are  in  most  cases  divided  in  addition 
to  nerves,  so  that  the  investigation  of  the  loss  of 
motor  power  may  be  attended  with  considerable 
difficulty ;  but  no  such  difficulty  exists  in  the  exami- 
nation of  sensation,  for  loss  of  sensibility  is  always 
present  in  cases  of  division  of  the  median  or  ulnar 
nerves,  the  nerves  commonly  affected  in  this  way, 
and  the  division  of  tendons  in  addition  entails  a  loss 
of  deep  sensibility,  so  that  no  mistakes  are  likely  to 
arise  from  mistaking  deep  for  superficial  sensibility. 

Diagnosis. — No  difficulty  should  arise  in  the 
diagnosis  between  complete  and  incomplete  division 
after  the  fourteenth  day  if  the  examination  be  con- 
ducted on  the  lines  I  have  laid  down.  When  the 
injury  is  of  sufficient  standing  to  allow  of  recovery, 
or,  in  watching  the  after-progress  of  the  patient,  it 
is  impossible  without  this  complete  examination  to 
be  certain  if  regeneration  is  taking  place  and  to 
what  stage  it  has  advanced. 

It  must  be  remembered  also  that  if  the  limb  has 


60  m JURIES    OF    NERVES 

been  allowed  to  remain  in  a  bad  position  and  no 
attempt  made  to  correct  the  deformity^  sucli^  for 
example_,  as  the  claw  hand  o£  nlnar  paralysis,  this 
will  in  all  probability  remain  permanent ;  although 
the  muscles  have  regained  their  power  of  reacting  to 
the  interrupted  current  they  remain  paretic  and 
wasted.  This  is  also  not  uncommonly  seen  in  cases 
of  brachial  birth  paralysis  which  have  been  allowed 
to  recover  without  any  attempt  being  made  to  correct 
the  deformity  resulting  or  to  attempt  to  prevent 
over-stretchino'  of  the  affected  muscles  or  contracture 
in  their  opponents.  I  have  known  cases  such  as 
these  lead  to  errors  in  diagnosis  and  the  patient  has 
been  submitted  to  futile  operations  in  consequence. 


CHAPTER    V 

Differential  Diagnosis — From  Lesions  of  Spinal  Cord  and  Eoots ; 
Motor,  Sensory — From  Hysterical  Manifestations;  Sensory, 
Motor — From  Iscli^mic  Contractiu-e. 

Difficulties  may  arise  in  tlie  diagnosis  of  lesions  of 
the  peripheral  nerves  from  those  of  nerve  roots^  of 
the  spinal  cord,  from  hysterical  conditions  and  from 
Volkmann^s  ischgemic  contracture. 

Spinal  cord. — Difficulties  in  diagnosis  arise  in  most 
cases  only  in  injuries  of  the  cervical  and  sacral 
regions  of  the  cord  due  to  fracture  dislocations  of 
the  spine. 

When  the  spinal  cord  is  affected  we  have  to  deal 
not  only  with  the  effect  of  destruction,  or  interference 
with,  the  function  of  the  segment  of  the  spinal  cord  in 
which  the  lesion  is  situated  and  of  the  fibres  entering 
into  it  at  this  level,  but  also  with  interference  with 
the  conduction  of  impulses  passing  up  and  down  the 
cord.  The  resulting  disturbance  of  motion  and  sensi- 
bility differs  very  considerably  from  that  seen  after 
a  peri^Dheral  nerve  injury. 

Motion. — A  lower  segment  lesion,  that  is,  a  lesion 
of   the    lower  motor  "  neurone/'  anywhere  from    its 


62  INJUEIES    OF    NEEYES 

orio'in  in  an  anterior  liorn  cell  to  its  distribution  in 
tlie  muscle  it  supplies^  produces  a  flaccid  paralysis 
accompanied  by  changes  in  tlie  electrical  excitability 
of  the  affected  muscle^  and  if  complete^  the  reaction 
of  degeneration.  It  should  be  remembered  that 
the  motor  fibre  may  be  affected  at  the  anterior 
horn  cells  as  the  result  of  an  injury  or  anterior 
poliomyelitis  or  in  the  anterior  root  or  peripheral 
nerve.  In  all  these  situations  motion  may  be  affected 
without  sensibility  ;  in  lesions  of  anterior  horn  cells 
or  anterior  roots  motion  is  affected  alone ;  in  the 
peripheral  nerves  sensibility  is  usually  affected  at 
the  same  time. 

The  grouping  of  the  affected  muscles  may  at  once 
denote  the  peripheral  or  central  position  of  the  lesion. 
For  example^  the  deformity  produced  by  an  injury 
of  the  ulnar  nerve  is  different  from  the  true  claw- 
hand  produced  by  a  lesion  of  the  first  dorsal  root  or 
segment,  and  in  the  same  way  paralysis  of  the 
extensors  of  the  fingers  and  thumb  and  the  ulnar 
extensor  of  the  wrist,  while  the  supinator  longus  aild 
radial  extensors  of  the  Avrist  remain  unaffected,  at 
once  denotes  the  root  or  central  position  of  the 
lesion. 

But  the  Erb-Duchenne  or  peroneal  group  of 
muscles  may  suffer  as  the  result  of  interference 
with  their  supply  in  the  anterior  horn,  root 
or  peripheral  nerve.  In  the  former  case  (Erb- 
Duchenne)   the  diagnosis  may  rust  entirely  upon  the 


SPINAL    CORD    AND    ROOTS  63 

history,  for  even  section  of  tlie  anterior  primary 
division  of  the  fifth  cervical  nerve,  the  nerve  supply- 
ing this  group,  does  not  produce  any  sensory  loss.  In 
the  latter  case,  if  the  lesion  is  in  the  root  or  anterior 
horn  cells,  the  tibialis  anticus  often  escapes  and  there 
is  no  loss  of  sensibility — an  impossibility  if  the  motor 
affection  were  due  to  injury  of  the  external  popliteal 
nerve  which  supplies  these  muscles. 

It  is  impossible  to  diagnose  by  symptoms  alone 
between  a  lesion  limited  to  the  anterior  horn  cells 
and  a  lesion  of  an  anterior  root.  The  necessity  for 
such  a  diagnosis  fortunately  does  not  often  arise,  and 
when  it  does  the  history  of  the  case  usually  makes 
the  diagnosis  clear.  Injury  to  anterior  roots  occurs 
chiefly  in  the  cauda  equina ;  localised  destruction 
of  anterior  horn  cells  as  the  result  of  disease ;  it  is 
rarely  these  are  affected  by  an  injury  without  causing 
some  loss  of  conduction  in  the  cord. 

The  term  '^  anterior  root "  should  be  strictly  limited 
to  its  anatomical  meaning  and  not  used,  as  is  so  often 
the  case,  to  denote  the  anterior  primary  division  of  a 
nerve. 

Paralysis,  the  result  of  an  uj^per  segment  lesion, 
that  is,  of  the  upper  motor  fibres  from  the  cortex  to 
their  termination  in  the  cord,  is  easily  distinguished 
by  the  electrical  reactions  of  the  affected  muscles 
remaining  unchanged  and,  in  most  cases,  by  the 
spasticity  present. 

Seub-atiun. — It  was  shown  by  Head,  Rivers  and  the 


64  INJURIES    OF    NERVES 

author  that  the  afferent  impulses  are  grouped  in  an 
entirely  different  manner  when  the  spinal  cord  is 
reached_,  hence  their  interrui^tion  will  lead  to  entirely 
different  sensory  changes.  The  tracts  in  the  spinal 
cord  are  devoted  to  the  conduction  of  impulses 
concerned  with  pain_,  heat^  cold  and  touch ;  it  is  no 
long-er  a  question  of  epicritic_,  protopathic  and  deep 
sensibility. 

This  subject  has  been  fully  worked  out  by  Head 
and  Thompson  J  and  the  following  is  drawn  from  their 
article  on  the  subject. 

Pain. — After  division  of  a  peripheral  nerve  or 
posterior  root^  those  parts  only  become  insensitive  to 
the  pain  of  deep  pressure  which  are  at  the  same  time 
totally  insensitive  to  the  tactile  element  of  the 
stimulus.  Unless  all  deep  sensibility  be  abolished 
pain  will  be  caused  by  excessive  pressure.  But  if 
the  lesion  lies  within  the  spinal  cord  sensibility  to 
pain  is  abolished  as  a  whole  whatever  the  form  of 
stimulation. 

Heat  and  cold. — When  the  lesion  is  within  the 
spinal  cord  sensibility  to  heat  may  be  abolished 
without  sensibility  to  cold.  Y/hen  sensibility  to  heat 
or  to  cold  is -abolished  in  consequence  of  an  intra- 
medullary lesion,  the  patient  no  longer  appreciates 
any  warm  or  hot  stimulus  ;  in  the  same  way_,  when 
sensibility  to  cold  is  abolished  the  patient  no  longer 
appreciates  any  cold  or  cool  stimulus.  All  distinction 
between    the    minor    and    the    extreme    degrees    of 


SPINAL    COKD  65 

temperature  is  lost,  the  appreciation  of  heat  or  of  cold 
is  lost  as  a  whole.  The  patient  may  be  insensitive 
to  all  degrees  of  temperature  and  yet  be  able  to 
appreciate  the  lightest  touch  and  discriminate  the 
points  of  a  pair  of  compasses — conditions  which  can 
never  occur  from  a  lesion  of  a  peripheral  nerve  only. 

Touch,  superficial  and  deep. — After  division  of  a 
nerve  or  posterior  root,  light  touches  with  cotton- 
wool are  usually  not  appreciated,  though  deep  touch 
(pressure)  evokes  a  response.  But  when  the  lesion 
lies  within  the  spinal  cord  both  forms  of  touch  are 
affected  together. 

Passive  movement  and  position. — After  division  of 
peripheral  nerves  the  recognition  of  passive  move- 
ment and  of  the  position  into  which  any  part  of  the 
limb  has  been  placed  (passive  position)  is  associated 
with  the  integrity  of  deep  sensibility.  But  with  an 
intra-medullary  lesion  it  is  entirely  dissociated.  The 
patient  may  be  able  to  appreciate  passive  position  and 
movement  although  totally  insensitive  to  every  other 
sensory  stimulus,  or  vice- versa.  In  a  similar  way,  a 
patient  may  be  able  to  appreciate  all  varieties  of 
touch  perfectly,  and  yet  be  unable  to  discriminate 
two  points  (compass  test).  In  lesions  of  peripheral 
nerves  the  compass  test  is  always  affected  with  light 
touch. 

We  thus  see  that  a  rearrangement  of  impulses  takes 
place  within  the  spinal  cord  and  that  their  interrup- 
tion causes    loss  of  sensibility    to   pain,    heat,    cold, 

5 


66  IXJUIJIES    OF    NERVES 

or  tactile  sensibility  as  a  wliole  instead  of  to 
epicritic^  protopatliic^  and^,  in  some  cases_,  deep  sensi- 
bility as  occurs  wlien  tlie  continuity  of  a  peripheral 
nerve  is  interrupted. 

Put  briefly  tlie  important  points  are  as  follows  : 
After  division  of  a  peripheral  nerve  or  of  posterior 
roots  there  may  be  loss  of  epicritic_,  protopathic  and 
deep  sensibility.  After  division  of  a  peripheral 
nerve  the  loss  of  epicritic  sensibility  is  greater  than 
the  loss  of  protopathic;  after  division  of  posterior 
roots^  the  loss  of  protopathic  sensibility  exceeds 
in  extent  the  loss  of  epicritic.  But  when  the  injury 
affects  the  spinal  cord^  pain^  temperature  appreciation^ 
touch,  may  be  affected  separately.  Usually  light  and 
deep  touch  are  well  recognised  although  sensibility  to 
pain  and  to  temperature  is  absent. 

In  unilateral  lesions  of  the  spinal  cord  the  appre- 
ciation of  pain,  heat  and  cold  is  affected  on  the  side 
opposed  to  the  lesion,  passive  movement  and  position 
on  the  side  of  the  lesion  and  the  motor  affection. 

Hysterical  affections. — The  hysterical  limbs  of  women 
are  well  recognised ;  but  occurring  in  healthy  men, 
complicating,  as  they  may,  fractures,  dislocations,  or 
even  a  nerve  injury,  they  are  not  so  often  diagnosed. 
This  type  of  functional  nervous  disorder  may  follow 
any  form  of  injury ;  thus,  I  have  seen  anaesthesia  and 
paralysis  of  the  whole  hand  follow  a  burn  of  the 
thenar  eminoiico  in  a  woman,  and  a  fracture  of  the 
radius    in    a    boy    of    twelve.        It    may   complicate 


HYSTERICAL    AFFECTIONS  67 

recovery  from  operations;  in  one  case  that  came 
under  my  care  paralysis  of  the  upper  limb  was 
noticed  after  the  evacuation  of  a  large  abscess  in 
the  supra-clavicular  region_,  and  gave  rise  to  the 
opinion  that  the  brachial  plexus  had  been  injured. 

The  following*  is  a  typical  case^in  this  instance_, 
complicating  a  fracture  of  the  humerus. 

"  A  seaman^  aged  forty-four  years^  fractured  his 
humeriis  while  at  sea.  It  was  treated  by  the  master 
of  the  ship  and  kept  in  splints  for  six  weeks  ;  union 
was  perfect  and  the  position  good.  When  the 
splints  were  removed  it  was  found  that  the  limb  was 
'  completely  paralysed.^  He  was  sent  to  me  as  a 
case  of  injury  to  the  brachial  plexus. 

"  The  patient  was  a  robust  man  who  had  followed 
the  sea  for  thirty  years^  and  had  never  had  any 
serious  illnesses. 

"  All  the  muscles  of  the  right  upper  limb  were 
wasted^  the  arm,  forearm  and  hand  were  paralysed 
and  the  muscles  flaccid.  The  skin  was  bluish  in 
colour_,  and  cold. 

''  Over  the  whole  of  the  upper  limb  he  was  insensi- 
tive to  all  forms  of  stimulation,  including  deep 
touch,  and  the  upper  limit  of  the  sensory  loss  sur- 
rounded the  limb  as  a  ring  (stocking  anaesthesia). 
The  distribution  and  nature  of  the  loss  of  sensibility 
at  once  demonstrated  that  it  could  not  have  resulted 
from  injury  to  peripheral  nerves  or  spinal  cord.  On 
testing     the     muscles     electrically    they     responded 


68  INJURIES    OF    NERYES 

readily  to  stimulation  with  the  interrupted  current_, 
as  is  always  the  case  in  this  affection/^ 

The  condition  may  follow  an  injury  in  either  sex^ 
but  is  more  often  seen  in  the  male.  So  far  as  I 
have  been  able  to  ascertain  they  are  usually  healthy 
individuals  and  may  show  no  other  hysterical  mani- 
festation. Careful  examination  will  sometimes  reveal 
the  typical  hysterical  change  in  the  field  of  vision_, 
a  contraction  of  the  whole  field  of  vision^  more 
marked  on  the  affected  side  Avith  contraction  of  the 
colour  field^  appreciation  of  blue  being  diminished 
first  in  contra- distinction  to  the  diminution  of  the 
field  of  vision  for  red^  seen  in  patients  with  organic 
disease. 

As  a  rule  loss  of  sensibility  and  paralysis  are  both 
present^  but  either  may  be  found  alone^  the  former 
more  often  than  the  latter.  The  loss  of  sensibility  is 
to  all  forms  equally  (including  deep  touch) ^  a  variety 
of  loss  that  does  not  occur  after  any  peripheral 
nerve,  posterior  root^  or  spinal  cord  injury ;  its 
upper  limit  usually  surrounds  the  limb,  often  at  the 
level  of  a  joint,  and  all  forms  of  sensibility  are  lost 
up  to  the  same  level.  In  the  upper  limb  the  loss  of 
sensibility  may  cover  the  ]3ectoralis  major  muscle  in 
front  and  the  scapula  behind  (fore-quarter  type). 

The  paralysis  may  persist  unchanged  for  years 
and  marked  muscular  wasting  will  then  occur.  It 
is,  as  a  rule,  flaccid,  and  no  attempts  are  made  to 
throw  the  affected  muscles  into  action,  but  occasion- 


HYSTERICAL    AFFECTIOXS  69 

ally  a  patient  is  met  with  in  whom  attempts  to 
perform  a  movement — for  example^  flexion  of  the 
elbow — causes  an  equal  and  simultaneous  contraction 
of  both  flexors  and  extensors_,  rendering  the  dia- 
gnosis easy.  Contractures  may  be  present^  differing 
from  those  seen  as  the  result  of  iujuries  to  nerves_,  in 
that  all  the  muscles  are  aifected^  not  only  those  on 
the  same  side  of  the  limb  as  the  contracture.  For 
example^  in  a  contracture  at  the  elbow  of  a  hysterical 
limb^  not  only  are  the  flexor  muscles  rigid^  but  any 
attempt  to  further  flex  the  forearm  is  met  by  con- 
traction of  the  triceps. 

No  diflaculty  should  arise  in  the  recognition  of 
most  examples  of  this  condition  :  the  loss  of  sensi- 
bility is  diagnostic  and  the  flaccid  paralysis  with 
retention  of  electrical  reactions  typical.  But  when 
complicating  a  nerve  injury  it  gives  rise  to  difiiculty. 
It  explains  many  of  the  recorded  cases  of  nerve 
^'  concussion"  in  which  paralysis  of  the  w^hole  of  a 
limb  results  from  a  gunshot  injury  which  may  or  may 
not  have  injured  one  nerve.  In  the  latter  case  the 
widespread  symptoms  rapidl}^  clear,  leaving  signs  of 
involvement  of  one  definite  nerve. 

In  Civil  practice  I  have  seen  several  examples  of 
this  condition  some  time  after  the  original  accident, 
but  have  not  yet  observed  it  at  the  time  of  infliction 
of  the  nerve  injury. 

Careful  attention  to  symptoms  will  enable  the 
diagnosis  to  be  made.        The  paralysis  may  be  wide- 


70  INJURIES    OF    NERYES 

spread  and  affect  muscles  central  to  the  site  of  the 
nerve  injury^  but  occasionall}?'' — for  example^  after 
division  of  the  median  or  ulnar  nerves  at  the  wrist- 
all  the  intrinsic  muscles  of  the  hand  are  found  to  be 
paralysed^  and  only  the  electrical  examination  reveals 
the  functional  nature  of  the  paralysis  of  one  group 
of  these.  In  testing  sensibility  the  remarkable 
correspondence  of  the  upper  limit  to  all  forms  of 
sensibility  and  the  affection  of  deep  sensibility  should 
make  the  diagnosis^  even  in  these  cases^  easy. 

Volkmami's  ischsemic  contracture. — It  sometimes 
happens  that  difficulty  occurs  in  connexion  with  the 
diagnosis  of  this  condition.  Several  cases  of  this 
nature  have  been  recorded  as  unusual  examples  of 
nerve  injury. 

The  contracture  most  often  results  from  the 
injurious  pressure  of  tightly-applied  splints^  and 
nerves  may  suffer  as  well  as  muscles.  In  a  typical 
example,  arising  after  splint-]3ressure  in  the  forearm^ 
it  will  be  found  that  the  forearm  is  held  pronated,  with 
the  wrist  and  fingers  flexed  ;  supination  of  the  fore- 
arm and  active  or  passive  extension  of  the  wrist  or 
fingers  is  impossible.  The  contracted  muscles  are 
not  paralysed  and  react  normally  to  both  interrupted 
and  constant  currents^  hence  the  name  "  ischasmic 
paralysis"  sometimes  given  to  this  condition  is  a 
misnomer. 

On  flexing  the  wrist,   so  relaxing  the   contracted 
muscles,   the   fingers  can   be    extended,  and  on    ex- 


ISCHEMIC    CONTRACTURES  71 

tension  of  the  wrist  they  again  become  flexed,  showing 
tliat  the  condition  is  due  to  diminution  in  length  of 
the  affected  muscles. 

The  injury  to  the  median  and  ulnar  nerves  which 
so  often  complicates  the  condition  will  affect  the 
intrinsic  muscles  of  the  hand;  these  maybe  wasted 
and  paralysed  and  give  the  reaction  of  degeneration, 
and  there  may  be  the  usual  loss  of  sensibility  seen 
after  complete  division  of  these  nerves,  but  as  a  rule 
the  nerve  injury  is  incomplete. 


CHAPTER   VI 

The  Treatment  of  Nerve  Injuries — General  Lines  of  Treatment — 
Treatment  of  Nerve  Injuries  in  Accidental  Wounds — Primary- 
Suture — Subcutaneous  Injuries — Secondary  Suture — Treat- 
ment of  Nerve  Injuries  complicating  Fractures — Treatment 
of  Gunshot  Injuries. 

The  general  lines  of  treatment  of  any  nerve  injury 
are  tliese  :  to  maintain  the  nutrition  of  the  parts 
supplied  by  the  injured  nerYe_,  to  prevent  over- 
stretching of  the  paralysed  muscles  and  contracture 
in  the  opponent  muscles  until  conduction  is  restored, 
by  Nature  alone  or  aided  by  the  surgeon.  It  is 
therefore  obvious  that  operation,  although  in  many 
cases  essential,  is  but  one  step  in  the  treatment.  The 
patient,  and  in  some  cases  even  the  surgeon,  are 
prone  to  consider  that  when  the  ends  of  the  nerve 
have  been  united  by  operation  nothing  further 
remains  to  be  done.  This  erroneous  idea  is  respon- 
sible for  many  failures  in  complete  restoration  of 
function;  the  successful  result  of  the  operation 
depends  to  a  great  extent  upon  the  care  bestowed  on 
the  after-treatment,  carried  out,  it  may  be,  for  months 
or  even  years. 


TREATMENT  73 

In  every  case  of  nerve  injury  in  which  muscles  are 
paralysed^  these  muscles  must  be  kept  relaxed  by 
suitable  apparatus  until  voluntary  power  is  restored. 
This  essential  to  treatment  is  often  overlooked  and 
recovery  in  consequence  delayed  or  rendered  incom- 
plete. This  is  especially  seen  after  injuries  of  the 
ulnar  and  external  popliteal  nerves.  In  the  former 
case  the  ulnar  position  of  the  hand  often  becomes 
permanent  and  the  muscles  remain  atrophied^  although 
they  have  regained  their  excitability  to  stimulation 
with  the  interrupted  current^  in  the  latter^  recovery 
is  slow  and  the  talipes  equinus  may  render  a  sub- 
sequent tenotomy  necessary. 

The  splint  or  apjDaratus  used  must  be  removed 
daily  and  massage  and  systematic  passive  and  active 
movements  carried  out.  This  may  be  supplemented 
by  stimulation  with  the  interrupted  current,  and 
the  paralysed  muscles  excited  with  whichever  form 
of  current  they  will  respond  to — usually  the  con- 
stant. This  electrical  treatment  should  be  carried 
out  whenever  possible,  but  is  not  so  necessary  as 
massage  and  movements ;  these  should  be  employed 
at  least  three  times  a  week,  if  possible  daily. 

The  patient  should  be  warned  that  slight  injuries 
may  produce  serious  results,  that,  for  example,  water 
not  unpleasantly  hot  to  unaffected  portions  of  the 
body  may  cause  blisters  to  appear  on  the  affected. 
No  work  should  be  done  with  the  affected  limb. 
Fortunately    this    is   possible    in    most    cases    owing 


74  INJURIES    OF    NERVES 

to  accident  insurance  and  workmen^s  compensa- 
tion. 

As  soon  as  voluntary  power  begins  to  return 
splints  may  be  removed ;  the  recovering  muscles  must 
be  actively  exercised  every  day  and  massage  con- 
tinued until  recovery  is  complete. 

Cases  submitted  to  suture  are  treated  on  these 
lines  as  soon  as  the  wound  has  healed. 

Treatment  of  nerve  injury  in  accidental  wounds. — 
It  should  be  a  matter  of  routine  to  examine 
for  evidence  of  nerve  injury  all  patients  with 
accidentally  inflicted  wounds.  This  is  often 
omitted_,  sometimes  with  serious  consequences  to 
the  patient  ;  the  prognosis  of  secondary  suture  of 
certain  nerves  is  much  more  unfavourable  than 
primary.  These  wounds  are  particularly  common 
in  the  region  of  the  wrist,  and  are  usually  caused 
by  broken  glass,  windows  or  bottles,  and  sever 
in  most  instances  tendons  in  addition  to  nerves. 
The  condition  of  sensibility  and  the  action  of  the 
intrinsic  muscles  of  the  hand  should  be  investigated 
before  any  attempt  is  made  to  deal  with  the  divided 
structures. 

After  this  examination,  the  skin  surrounding  the 
wound  is  thoroughly  cleaned  and  the  nerve  exposed 
through  an  incision  of  sufficient  length  and  examined  ; 
it  is  usually  necessary  to  make  the  incision  at  right 
angles  to  the  wound  causing  the  injury.  In  all 
nerve  operations  asepsis  is  essential  ;  in  no  branch  of 


PRIMARY    SUTURE  75 

surgery  does  slight  supj^nration  interfere  so  greatly 
witli  the  success  of  the  operation. 

If  the  nerve  is  found  to  be  incompletely  divided, 
the  gap  should  be  closed  by  a  catgut  stitch  to  bring 
the  cnt  axis  cylinders  again  into  apposition  and  to 
prevent  the  ingrowth  of  fibrous  tissue. 

If  the  nerve  is  completely  divided  primary  suture 
must  be  performed. 

Primary  suture. — The  modern  operation  of  primary 
suture  is  of  comparatively  recent  date.  It  is  said  to 
have  been  performed  first  by  Baudens  in  1836,  who 
sutured  all  the  nerves  of  the  brachial  plexus  with 
the  exception  of  the  musculo-spiral,  which  were 
divided  in  a  sword  cut  of  axilla.  But  it  is  only 
since  1864  that  it  has  been  a  recognised  method  of 
treatment,  Nelaton^s  being  the  first  of  the  more 
recent  cases. 

In  the  operation  of  joi'iniary  suture  it  is  necessary 
to  bring  the  divided  ends  of  the  nerve  into  apposition, 
and  to  jDrevent,  if  possible,  the  ingrowth  of  fibrous 
tissue  and  adhesion  of  the  junction  to  surrounding- 
structures. 

If  the  ends  of  the  nerve  are  lacerated  they  should 
be  trimmed  transversely  with  a  sharp  scalpel.  Scissors 
should  never  be  used  for  the  purpose ;  their  crushing- 
action  may  prevent  recovery.  It  sometimes  happens 
that  a  nerve  is  divided  at  two  or  more  levels,  a 
portion  being  loose ;  this  should  be  sutured  in.  It 
is  unusual  to  find  so   great   a  portion   of  the  nerve 


76  INJURIES    OF    NERVES 

destroyed  that  it  is  impossible  to  bring  the  ends 
into  apposition;  for  the  treatment  of  this  compli- 
cation the  reader  is  referred  to  Chapter  VII. 

Sterile  catgut  is  the  best  suture  material  for 
nerves.  It  is  not  necessary  to  use  hardened  gut 
unless  there  is  tension  on  the  stitch,  but  if  con- 
siderable portions  of  the  ends  of  the  nerve  have  had 
to  be  removed  on  account  of  laceration,  catgut, 
hardened  to  resist  absorption  for  at  least  fourteen 
days,  should  be  employed.  The  suture  should  be 
passed  with  a  round  needle,  both  needle  and  suture 
being  as  small  as  possible.  The  suture  should  be 
passed  through  the  whole  thickness  of  the  nerve  at 
right  angles  to  its  axis  and  tied  with  just  sufficient 
force  to  bring  the  ends  into  apposition.  It  is  some- 
times said  that  the  catgut  should  not  be  passed 
through  the  whole  substance  of  the  nerve  on  account 
of  the  bad  results  which  would  arise  if  infection  were 
to  occur.  But  paraneurotic  suture  is  an  operation 
involving  much  more  handling  of  the  nerve,  if  the 
sheath  of  a  nerve  the  size  of  the  median  or  ulnar  is 
to  be  sutured  ;  in  my  opinion  the  method  which  I 
have  recommended,  passing  the  suture  through  the 
whole  thickness  of  the  nerve,  is  the  one  least  open 
to  objection.  In  most  cases  it  is  only  necessary 
to  use  one  stitch.  The  nerve  should  be  handled 
with  extreme  gentleness  and  the  whole  end  of  the 
nerve  never  grasped  in  the  forceps  ;  the  sheath  of  the 
nerve  only  should  be  picked    up   with   fine    toothed 


PRIMARY    SUTURE  77 

forceps  and  the  nerve  steadied  in  this  way  while  the 
suture  is  being  passed. 

Silk  should  never  be  used  as  a  suture  material. 
It  remains  as  a  foreign  body  in  the  nerve  and  may 
give  rise  to  trouble  months  after  primary  suture. 
In  one  case  that  came  under  my  notice,  following 
primary  suture  of  the  median  nerve,  restoration  of 
sensibility  was  almost  complete  and  motor  power  had 
returned  to  the  affected  muscles,  when  the  occurrence 
of  inflammation  around  the  silk  suture  used  to  unite 
the  ends  of  the  nerve  put  back  the  condition  of  the 
part  to  that  which  was  present  immediately  after  the 
accident;  the  symptoms  again  became  those  of  com- 
plete division  of  the  nerve.  After  evacuation  of  the 
abscess  and  removal  of  the  stitch,  recovery  was 
exceedingly  slow  and  was  not  complete  many  months 
after  the  time  usually  taken  in  primary  suture  of  the 
median  nerve. 

Not  only  must  the  ends  of  the  nerve  be  brought 
together  by  suture,  but  means  should  be  taken  to 
prevent  the  ingrowth  of  fibrous  tissue  between 
the  nerve  ends,  and  the  junction  from  becoming 
adherent  to  surrounding  parts.  For  this  purpose 
I  use  chromicised  Cargile  membrane.  This  resists 
absorption  in  the  tissues  certainly  for  five  weeks, 
and  does  not  cause  irritation.  I  have  used  it  now 
in  many  cases  of  nerve  and  tendon  injury  and  also 
in  cerebral  surgery  and  have  never  found  it  give 
rise  to  trouble.      Many  other  substances  have  been 


78  INJURIES    OF    NERTES 

recommended  from  time  to  time — decalcified  bone 
tubes  (Yanlair)^  gelatine  tubes  (Lotlieisen)^  animars 
artery  (Foramitti)^  paraffin  wax  (Murpliy). 

After  primary  suture  of  a  nerve  in  an  accident- 
ally inflicted  wound  it  is  always  Avise  to  put  in  a 
drain  for  a  short  time  ;  it  can  usually  be  removed 
in  four  and  twenty  hours.  After  suture  of  the 
skin  wound  the  limb  must  be  put  up  on  a  splint  so 
arranged  that  no  tension  is  thrown  upon  the  junc- 
tion and  the  paralysed  muscles  are  relaxed.  The 
further  treatment  is  on  the  lines  I  have  already  laid 
down. 

Treatment  of  subcutaneous  injuries. — All  the  signs  of 
complete  division  may  be  present  as  the  result  of  an 
injury  of  this  nature  ;  there  is  no  sign  by  which  Ave 
can  tell  if  the  nerve  has  been  ruptured  or  injured  as 
the  result  of  compression,  in  other  words^  if  the  injury 
is  anatomical  or  physiological_,  and  in  many  cases^  at 
first,  if  it  is  complete  or  incomplete. 

If  seen  immediately  after  the  accident,,  the  limb 
should  be  put  at  rest  on  a  splint  with  the  paralysed 
muscles  relaxed.  Daily  massage  should  be  employed 
until  such  time  has  elapsed  as  Avill  enable  the 
diagnosis  of  the  degree  of  the  injury  to  be  made.  If 
at  the  end  of  a  fortnight  the  reaction  of  degeneration 
has  developed  in  the  paralysed  muscles,  the  nerve 
should  be  exposed.  It  may  be  found  completely 
ruptured  ;  more  often  it  is  swollen  and  firm  at  the 
seat  of  the  injury.      This  damaged  portion  should  be 


SECONDARY    SUTURE  79 

removed  and  the  ends  brought  into  contact.  If  no 
change  can  be  discovered  in  the  condition  of  the 
nerve^  the  wound  should  be  closed. 

When  the  division  is  obviously  incomplete, 
relaxation  of  the  muscles  is  to  be  kept  up  Avith 
daily  massage  until  voluntary  power  returns,  when 
the  splint  may  be  discarded  and  active  movements 
encouraged.  The  massage  should  be  continued 
until  recovery  is  complete. 

Sometimes  a  nerve  becomes  secondarily  involved 
in  fibrous  tissue,  or  pressed  upon  by  bone,  or  in 
a  case  of  incomplete  division,  in  spite  of  appropriate 
treatment  the  condition  does  not  improve.  Explora- 
tion should  be  undertaken  in  these  cases,  the  nerve 
freed,  the  cause  of  the  pressure  removed  and  means 
taken  to  prevent  the  nerve  from  becoming  adherent 
by  surrounding  it  by  one  of  the  substances  already 
mentioned ;  for  this  purpose  I  prefer  Cargile  mem- 
brane. 

Secondary  suture. — This  operation  is  of  more 
recent  date  than  primary  suture.  Said  to  have  been 
first  performed  by  Nelaton  in  1864,  it  was  first 
carried  out  in  this  country  by  Jessop  in  1871. 

Various  meanings  have  been  attached  to  the  term 
'^secondary  suture  '^  ;  it  has  been  described  as  suture 
after  the  first  twenty-four  hours.  The  author  uses 
the  term  to  mean  suture  after  degeneration  has  taken 
place  in  the  peripheral  end  of  the  nerve. 

Secondary  suture  should  be  unknown  after  injury 


80  INJURIES    OF    NERVES 

to    nerves    in    wounds  ;     but    in    the   case     of    sub- 
cutaneous injuries  it  may  be  unavoidable. 

Before  proceeding  to  operation  a  careful  examina- 
tion is  necessary  in  order  to  discover  liow  much 
improvement  is  likely  to  ensue  as  tbe  result  of  the 
operation.  The  time  after  the  injury  at  which  opera- 
tion is  undertaken^  certainly  up  to  three  years^  seems 
to  have  little  influence  on  the  time  of  recovery^  and 
there  is  no  reason  why  success  should  not  be  obtained 
at  much  longer  periods^  although  no  entirely  satis- 
factory case  has  been  recorded.  Of  more  importance 
than  the  time  after  the  accident  is  the  nature  of  the 
original  injury,  if  an  incised  wound,  its  manner  of 
healing  ;  suppuration  in  the  original  wound  seriously 
diminishes  the  chance  of  complete  recovery. 

The  condition  of  the  muscles  and  joints  should  be 
investigated.  Muscles  which  have  been  overstretched 
for  months  are  unlikely  to  have  their  function  com- 
pletely restored,  although  they  may  regain  voluntary 
power  and  electrical  excitability  as  the  result  of  the 
operation.  For  example,  the  ulnar  position  of  the 
fingers  met  with  after  division  of  the  ulnar  nerve 
rarely  or  never  disappears  after  secondary  suture. 
The  interossei  muscles  have  been  lengthened,  the 
extensors  of  the  fingers,  the  ligaments  around  the 
metacarpo-phalangeal  and  inter-phalangeal  joints 
contracted. 

The  electrical  reactions  must  be  tested.      If  there 
is  no  reaction  to  stimulation  with  the  constant  current 


SECONDARY    SUTURE  81 

it  is  probable  that  muscular  recovery  is  impossible, 
but  this  opinion  must  not  be  given  on  one  examination 
only,  however  carefully  carried  out. 

From  the  point  of  view  of  sensation  it  is  always 
worth  while  attempting  secondary  suture,  especially 
if  "  trophic  ulcers ''  are  present,  for  Dr.  Head  and 
the  author  showed  that  the  fibres  upon  which  the 
integrity  of  the  trophic  condition  of  the  skin  depend, 
regenerate  under  conditions  which  render  recovery  of 
epicritic  sensibility  and  motor  power  unlikely. 

The  operation  of  secondary  suture  may  be  divided 
into  three  stages. 

(1)  Identification  of  the  ends  of  the  nerve. 

(2)  Freeing  and  freshening  the  ends  of  the  nerve. 

(3)  Re-establishment  of  anatomical  continuit3^ 

(1)  The  incision  should  be  made  over  the  line  of 
the  nerve  and  be  of  sufficient  length  to  expose  the 
trunk  well  above  and  below  the  seat  of  the  injury. 
The  nerve  should  be  traced  from  above  and 
below;  any  attempt  to  find  it  directly  at  the  seat  of 
the  injury  will  only  lead,  in  most  cases,  to  unneces- 
sary damage  being  inflicted  on  the  nerve. 

(2)  The  bulb  with  the  fibrous  tissue,  which  is 
usually  found  surrounding  and  uniting  the  two  ends, 
is  then  well  freed  and  the  nerve  stretched.  After 
this  has  been  done  the  bulb  on  the  central  end  is 
removed  with  a  sharp  scalpel.  From  the  lower  end 
only  the  fibrous  upper  extremity  need  be  removed  ; 
the  whole   of  the   lower  end  of  the  nerve  is  in  the 

6 


82  INJURIES    OF    NERVES 

same  condition^  so  tliat  it  is  useless  cutting  section 
after  section  in  tlie  hope  of  finding  sometliing  which 
looks  less  like  fibrous  tissue  and  more  like  nerve. 

(3)  Catgut  should  be  used  for  suture  material^  and 
it  is  best  to  use  catgut  hardened  to  resist  absorption 
for  about  fourteen  days.  The  junction  and  the  freed 
portion  of  the  nerve  are  then  surrounded  with  Cargile 
membrane. 

It  often  happens  that  the  ends  do  not  come  readily 
into  apposition  after  the  necessary  amount  of  nerve 
ends  have  been  removed ;  it  was  for  this  reason  that 
the  preliminary  stretching  was  recommended.  This 
will  give  fully  an  inch  in  the  upper  limb^  and  com- 
bined with  relaxation  of  all  the  joints  over  which  the 
nerve  passes^  will  rarely  fail  to  enable  the  ends  to 
be  brought  into  contact.  If  a  gap  is  still  left  one 
of  the  methods  described  in  the  following  chapter 
should  be  adopted. 

After  closure  of  the  wound  the  limb  should  be  put 
up  so  that  there  is  no  tension  on  the  nerve  and  the 
paralysed  muscles  are  relaxed.  The  position  neces- 
sary to  prevent  tension  on  the  junction  must  be 
maintained  until  the  wound  is  soundly  healed  and 
then  very  gradually  corrected. 

Nerve  injuries  complicating'  fractm^es. — The  nerve 
may  be  injured  at  the  time  of  the  accident,  ruptured^ 
lacerated,  pressed  upon  by  the  fractured  end  of  the 
bone  or  nipped  between  the  fragments.  In  primary 
injury    to    the  musculo-spiral  nerve    complicating   a 


COMPLICATINa    FKACTUHES  83 

fracture  of  the  humerus,  operation  should  be  carried 
out,  the  condition  of  the  nerve  investigated  and  the 
appropriate  treatment  adopted.  Means  should  also 
be  taken  to  mechanically  fix  the  fracture.  The  same 
rule  should  be  followed  in  primary  involvement  of 
the  external  popliteal  in  a  fracture  of  the  fibula. 

In  most  cases,  however,  the  nerve  injury  is  not  dis- 
covered until  the  splints  are  removed ;  in  many  of 
these  the  nerve  involvement  is  undoubtedly  secondary. 
The  rules  for  treatment  in  these  cases  are  simple. 
If  the  signs  of  complete  division  are  present,  opera- 
tion must  be  performed;  the  nerve  should  be  ex- 
posed above  and  below  the  seat  of  the  fracture  and 
traced  towards  it.  The  nerve  may  be  found  rup- 
tured, but  more  often  involved  in  callus  or  fibrous 
tissue  and  altered  in  shape  and  consistency,  usually 
being  thin  and  fibrous;  when  found  completely 
divided  anatomically,  secondary  suture  should  be 
carried  out.  In  the  complete  physiological  division 
the  damaged  portion  should  be  excised  and  the  con- 
tinuity of  the  nerve  restored,  unless  the  nerve  be 
found  little  altered,  when  freeing  and  wrapping  with 
Cargile  membrane  may  first  be  tried.  If  no  improve- 
ment occurs  in  a  few  weeks  then  the  damaged  por- 
tion must  be  resected. 

When  the  signs  are  those  of  incomplete  division, 
the  limb  should  be  kept  at  rest  and  the  usual  treat- 
ment carried  out.  If  improvement  does  not  occur  the 
nerve  must  be  cut  down  upon  and  tlie  cause  of  the 


84  INJURIES    OF    NERVES 

pressure  removed.  It  sometimes  happens  that  the 
involvement  comes  on  some  weeks  or  months  after 
the  injury  ;  in  these  cases  operation  should  be  per- 
formed without  delay. 

Treatment  of  gunshot  wounds. — These  should  be 
treated  upon  the  lines  already  laid  down,  remember- 
ing that  primary  suture  is  inadvisable  in  most  cases 
under  ■  the  conditions  obtaining  in  war  time.  In 
other  respects  the  general  rules  apply.  The  limb 
should  be  kept  at  rest  and  the  injury  treated  as  if 
subcutaneous. 


CHAPTER   VII 

Plastic  Operations  on  Nerves — Metlaods  available  to  restore  con- 
tinuity —  Nomenclature  —  Nerve  Transplantation  —  Nerve 
Anastomosis — Nerve  Crossing. 

When  exposing  the  ends  of  a  nerve  in  order  to 
perform  secondary  suture,  after  the  excision  of  a 
tumour  connected  with  a  nervCj  or  in  some  cases  of 
primary  nerve  injury^  it  may  be  found  that  in  spite 
of  nerve  stetching  and  of  flexion  of  the  joint  or 
joints  over  which  the  nerve  passes,  it  is  impossible 
to  restore  anatomical  continuity. 

Many  methods  have  been  suggested  from  time  to 
time  to  bridge  over  the  gap  left  between  the  ends 
of  the  nerve.  Those  which  have  proved  satisfactory 
may  be  put  into  one  of  four  groups. 

(1)  Transference  of  a  ^^ortion  of  nerve  from 
another   source   (nerve   transplantation).  • 

(2)  Provision  of  a  path  along  Avhicli  the  nerve 
may  regenerate  (tubular  suture,  flap  opera- 
tions,  etc.). 

(3)  Utilisation  of  neighbouring  nerves  (anasto- 
mosis). 

(4)  Shortening  the  limb  by  the  resection  of  bone. 
Nomenclatiu^e. — The  operation  of  the   transference 


86  INJURIES    OF    NERVES 

of  a  portion  of  nerve  from  another  source  has  been 
known  in  English-speaking  countries  as  '^  nerve 
grafting/^  But  this  term  conveys  a  different  mean- 
ing to  French  and  Grerman  surgeons  ;  nerve  grafting 
(greffe  nerveuse,  nercenjjropfung)  is  to  them  synony- 
mous with  nerve  anastomosis.  This  would  be  an 
insufficient  reason  for  change  had  the  term  '^  nerve 
grafting  ^^  been  used  consistently  by  English-speaking- 
surgeons  to  mean  nerve  transplantation.  But  of 
late_,  with  the  multiplication  of  operations  on  peri- 
pheral nerves^  it  has  been  used  loosely  to  mean 
sometimes  nerve  anastomosis^  sometimes  nerve  cross- 
ing, and  at  others  nerve  transplantation,  in  this  way 
causing  confusion  and  retarding  progress.  Again, 
the  operation  of  uniting  an  affected  to  a  neighbour- 
ing sound  nerve  has  been  spoken  of  as  nerve  grafting, 
nerve  implantation,  etc.  For  these  reasons  I  sug- 
gested that  the  term  "nerve  grafting"  be  allowed 
to  drop  and  the  name  "  nerve  transplantation " 
employed  in  its  stead. 

Under  the  term  "  nerve  anastomosis  "  two  distinct 
ope/ations  are  often  included :  (1)  In  which  axis 
cylinders  of  the  injured  nerve  are  brought  into 
contact  with  some  of  the  axis  cylinders  of  the  sound 
nerve  ;  this  is  the  operation  to  which  the  term  should 
be  restricted.  (2)  In  which  a  neighbouring  sound 
nerve  is  divided  completely  and  end-to-end  union 
carried  out  with  the  perijDheral  end  of  the  affected 
nerve ;    this  should  be  spoken  of  as  nerve  crossing. 


NERVE    TRANSPLANTATION  87 

We  liave  therefore  the  f  olio  win  o*  nomenclature  : 
nerve  transplantation^  nerve  anastomosis,  nerve 
crossing. 

Group  1,  Nerve  transplantation. — It  was  demon- 
strated by  PhilJipeanx  and  Yulpian  in  1870  that  a 
portion  of  the  lingual  nerve  of  a  dog  could  be 
transplanted  into  a  gap  in  the  hypoglossal,  restora- 
tion of  function  occurring  in  due  time.  It  was  at 
first  considered  that  the  transplanted  portion  of 
nerve  played  an  active  part,  and  Gluck  even  spoke 
of  its  healing  by  "  primary  union/^  meaning  thereby 
restoration  of  function  without  degeneration  in  the 
transplanted  portion  and  peripheral  end  of  the  nerve. 
Tillmans  was  the  first  to  suggest  that  a  transplanted 
portion  of  nerve  acted  only  as  a  scaffolding  for  the 
support  of  the  newly-formed  nerve-fibres.  Recently 
Ballance  and  Purves  Stewart  came  to  the  same  con- 
clusion as  the  result  of  their  experiments.  But  it 
has  been  pointed  out  by  Merzbacher  and  confirmed 
by  Marinesco  that  the  changes  which  take  place  in 
an  isolated  portion  of  nerve  inserted  between  the 
cut  ends  of  another  nerve  difi^er  when  the  trans- 
plant is  taken  from  the  same  animal  (auto-trans- 
plantation) or  from  one  of  the  same  species  (homo- 
transplantation)  from  those  which  occur  when  it  is 
taken  from  an  animal  of  another  species  (hetero- 
transplantation). In  the  last  instance  death  and 
necrosis  occur,  in  the  first  two,  degeneration,  which 
is  a  vital  process.      Forssman    found  in   his  experi- 


88  INJURIES    OF    NERYES 

mental  work  on  rabbits^  that  when  the  transplant 
was  obtained  from  another  rabbit  regeneration  took 
place  as  rapidly  as  after  primary  suture  ;  but  when 
taken  from  an  animal  of  another  species^  regenera- 
tion occurred  much  more  slowly^  and  in  some  cases  no 
regeneration  at  all  took  place. 

It  appears  therefore  as  the  result  of  ex]3eriment  that 
the  transplanted  portion  of  nerve  plays  an  active  part 
when  it  is  taken  from  the  same  animal  or  one  of  the 
same  species,  and  does  not  act  only  as  a  scaffolding 
for  the  new  nerve-fibres^  but  has  a  definite  influence 
on  regeneration  through  the  cells  of  the  nucleated 
sheath.      This  is  borne  out  by  the  clinical  evidence. 

JSTerve  transplantation  was  first  employed  in  treat- 
ment by  Albert  in  1876,  who  inserted  a  portion  of 
the  posterior  tibial  nerve  of  an  amputated  limb  into 
a  gap  in  the  median  nerve.  Mayo  Robson,  in  1888, 
was  the  first  to  perform  the  operation  in  this  country, 
and  his  was  the  first  successful  case  recorded.  Into 
a  gap  in  the  median  nerve,  due  to  the  resection  of  a 
portion  of  the  nerve  with  a  neuroma,  he  transplanted 
two  and  a  half  inches  of  the  posterior  tibial  nerve 
from  an  amputated  liiiilj.  '^Fhe  affected  muscles 
reacted  to  stimulation  with  the  interrupted  current 
nine  months  later  and  restoration  of  function  was 
complete  three  years  after  operation. 

After  examining  the  records  of  all  the  published 
cases  of  nerve  transplantation  I  came  to  the  conclusion 
that  the  clinical  results  bore  out  the  experimental  in- 


FLAP    OPERATIONS  89 

vestigations  of  Forsmann,  Merzbacher  and  Marinesco; 
tliey  were  incomparably  better  when  auto-  or  homo- 
transplantation  had  been  performed  than  after 
hetero-transplantation.  Thus  although  only  three 
out  of  eight  cases  of  auto-  and  homo-transplantation 
are  reported  at  a  sufficient  interval  after  operation 
to  admit  of  recovery^  two  of  these  recovered  com- 
pletely ;  one  showed  no  sign  of  motor  recovery  seven- 
teen months  after  operation.  On  the  other  hand,  out 
of  twenty-two  cases  of  hetero-transplantation,  sixteen 
are  recorded  at  an  interval  after  operation  which 
would  have  permitted  of  recovery.  Of  these  only  one 
can  be  definitely  said  to  have  recovered,  that  is  it  is 
the  only  case  in  which  a  complete  report  is  given, 
including  the  electrical  reactions  of  the  affected 
muscles,  but  perhaps  recovery  ensued  in  two  of  the 
remainder. 

Group  2. — There  is  one  operation  in  this  group 
that  must  be  shortly  mentioned  to  be  condemned — 
that  is,  the  operation  of  turning  Haps  of  nerve  from 
both  ends  to  bridge  over  the  gap.  This  method, 
recommended  and  employed  by  Letievant  under  the 
name  ''  autoplastic  nerveuse  a  lambeaux,^'  leaves  a 
complicated  wound  on  both  ends  of  the  nerve  and  on 
the  flaps  used  as  bridging  nuiterial,  which  must 
certainly  become  adherent  to  the  surrounding  struc- 
tures and  favour  the  ingrowth  of  fibrous  tissue. 
The  results  are  as  unfavourable  as  the  method  would 
lead  us  to  expect. 


90  INJURIES    OF    NERVES 

The  other  operations  in  this  group  aim  at  the  pro- 
vision of  a  path^  free  from  fibrous  tissue,  along  which 
the  new  axis  cylinders  may  develop.  This  was  first 
attempted  by  Assaky  in  his  ^'  union  at  a  distance  '' 
Avith  cato'ut  threads,  in  which  the  ends  of  the  nerve 
were  brought  as  near  as  possible  by  catgut  sutures, 
which  bridged  over  the  gap.  It  has  been  improved 
by  the  introduction  of  tubular  suture  (Vanlair),  in 
which,  in  addition,  the  ends  of  the  nerve  are  sur- 
rounded by  a  tube.  Various  materials  have  been 
used — decalcified  bone,  aluminium,  collodion,  and 
recently,  preserved  and  hardened  animals^  arteries, 
and  a  resected  portion  of  one  of  the  patient^s  super- 
ficial veins.  This  last  seems  the  best  form  of  tube 
to  employ. 

Tubular  suture  has  given  results  which  are  a  little 
better  than  those  given  by  hetero-transplantation. 

Group  3. — The  possibility  of  the  union  of  motor 
nerves  supplying  different  groups  of  muscles  at- 
tracted the  attention  of  investigators  at  an  early 
date.  Flourens,  in  1828,  was  successful  in  his 
attempt  to  cross  the  nerves  of  the  brachial  plexus  of 
a  fowl.  But  it  is  from  investigations  of  a  more 
recent  date  that  our  knowledge  of  the  subject  is 
obtained.  Manasse,  in  1898,  was  the  first  to  experi- 
mentally investigate  what  we  now  understand  as 
nerve  anastomosis ;  but  it  is  to  the  work  of  Kennedy, 
Kilvington,  and  Langley  and  Anderson,  that  our 
exact  knowledge  is  due. 


NERVE    ANASTOMOSIS 


91 


It  is  essential  to  separate  nerve  anastomosis  from 
nerve  crossing,  for  in  the  former  an  attempt  is  made 
to  bring  tlie  axis  cylinders  of  tlie  affected  nerve  into 
end-to-end  contact  with  some  of  those  in  the  sound; 
in  nerve  crossing  the  peripheral  end  of  the  affected 
nerve  is  united  end-to-end  with  the  central  portion 
of  a  divided  sound  nerve.  Nerve  crossing  was  first 
worked  out  experimentally,  but  surgery  led  the  way 


A.  B.  c. 

I'iG.  3. — Complete  peripheral  anastomosis,  showing  the  three 
methods  of  iinion.  The  affected  nerve  is  shaded  in  all  the 
figures  relating  to  nerve  anastomosis.  a.  Insertion  of 
peripheral  end  of  affected  into  vertical  slit  in  sound  nerve. 
B.  Insertion  of  peripheral  end  of  affected  nerve  into  a 
gap  in  the  sound  nerve,  produced  by  an  oblique  incision  ; 
c.  End-to-end  union,  with  fiaj)  raised  from  soimd  nerve. 

for  experimental  investigation   into  the  question    of 
nerve  anastomosis. 

Nerve  anastomosis. — Letievant  first  recommended 
this  operation  in  1873  under  the  name  of  "  greffe 
nervense.'^       He  had,  however,    no  opportunity   for 


92 


INJURIES    or    NERVES 


carrying  it  out.  Despres  (1876)  appears  to  have 
been  the  first  to  perform  it^  but  the  case  was  re- 
ported two  months  after  the  operation — too  early  a 
date  to  admit  of  recovery.  It  was  not  until  1897 
that  Sick  and  Sanger  reported  the  first  successful 
case.  Two  months  after  rupture  of  the  musculo- 
spiral  nerve  in  a  compound  fracture  of  the  humerus^ 


Fig.  4. — Partial  peripheral  anastomosis.     Can  also  be  car- 
ried ont  by  methods  b  and  c.  Fig.  5. 


a  flap  of  the  median  nerve  was  raised  and  the  peri- 
pheral end  of  the  musculo-spiral  united  end-to-end 
with  it.  Twenty-seven  months  later  all  the  muscles 
of  the  forearm  except  the  extensor  longus  pollicis 
acted  normally,  and  reacted  to  stimulation  with  the 
interrupted  current. 

Recently    much    attention    has    been    directed   to 
operations  of  this  nature  by  the  work  of  the  Ballances 


NERVE    ANASTOMOSIS  93 

and  Purves  Stewart  on  nerve  anastomosis  in  facial 
paralysis. 

The  results  of  tlie  operation  of  nerve  anastomosis 
have  been  most  encouraging.  Out  of  twelve  cases 
(excluding  those  in  which  the  operation  was  carried 
out  for  facial  paralysis  or  infantile  paralysis)  reported 


Fig.  5.— Complete  central  anastomosis.     Can  also  be  carried 
out  by  methods  b  and  c^  Fig.  5. 

sufficiently  long  after  the  operation^  oi\\j  two  were 
failures^  some  recovery  taking  place  in  all  the  others^ 
although  it  is  impossible  to  say  from  the  published 
reports  that  recovery  was  complete  in  any  case. 

Several  methods  of  nerve  anastomosis  are  possible. 
They  may  be  divided  into  the  peripheral  and  central^ 
the  partial  and  the  complete.  In  peripheral  anasto- 
mosis (Figs.  3,  4)  the  whole  or  part  of  the  peripheral 


94 


INJURIES    OF    NERVES 


end  of  the  affected  nerve  is  brouglit  to  tlie  sound 
nerve.  In  central  anastomosis  (Figs.  5^  Q),  the 
unaffected  nerve  is  divided  completely  or  partially 
and  its  central  united  to  the  affected  nerve. 

In  some  of  the  recorded  cases  of  nerve  anastomosis 
the  peripheral  end  of  the  affected  nerve  was  sutured 
to    the    sheath    of    the    sound;     the    failure    which 


Fig.  6. 


■Partial  central  anastomosis.     Can  also  be  carried 
out  by  methods  b  and  c.  Fig'.  3. 


resulted  was  to  be  expected.  It  should  be  the  aim 
of  the  surgeon  to  bring  the  cut  ends  of  axis  cylinders 
into  contact^  for  without  this^  union  with  the  central 
nervous  system  is  impossible.  This  end -to -end 
contact  may  be  brought  about  in  three  ways  (vide 
Fig.  3)  ;  in  the  case  of  small  nerves^  by  making 
a  vertical  slit  in  the  sound  nerve  sufficient  axis 
cylinders  are  divided  to  ensure  a  good  result;  but  in 
larger    nerves^    a    flap    should    be    raised    and    the 


NERYE    CROSSING  95 

affected  nerve  sutured  in  or  united  end-to-end  with 
it.  Raising  a  flap  and  uniting  it  end-to-end  with 
the  peripheral  end  of  the  affected  nerve  is  the  best 
method  to  adopts  as  it  avoids  the  possibility  of  the 
union  of  one  axis  cylinder  in  the  central  end  of  the 
sound  nerve  with  an  axis  cylinder  in  each  peripheral 
end. 

In  cases  of  nerve  injury  complete  peripheral  anas- 
tomosis is  the  variety  that  must  be  employed ;  it  is 
not  justifiable  to  completely  divide  a  sound  nerve. 

It  has  been  recommended  to  implant  the  central 
end  of  the  divided  nerve  also  into  the  sound  and 
so  use  the  sound  nerve  as  a  path  along  which 
new  nerve-fibres  may  make  connexion  between  the 
two  ends.  But  it  has  been  shown  that  the  axis 
cylinders  in  the  central  end  of  a  divided  nerve 
have  no  preference  for  those  of  its  own  central 
end^  but  will  just  as  readily  make  connexion  with 
those  in  the  peripheral  end  of  a  nerve  united  to  it. 
The  results  are  therefore  likely  to  be  better  if  the 
central  end  is  not  used,  for  the  cross  union  of  axis 
cylinders  which  must  result  makes  the  restoration  of 
perfect  co-ordination  unlikely. 

Nerve  crossing. — This  operation  was  first  carried 
oat  in  the  human  subject  by  Drobnik,  in  1879,  in  a 
case  of  facial  paralysis,  the  peripheral  end  of  the 
facial  being  united  end-to-end  with  the  divided 
external  branch  of  the  spinal  accessory  nerve.  It 
has    been  employed  chiefly  in    operations  upon  the 


96  INJURIES    OF    NERVES 

facial  nerve,  and  will  be  discussed   fully  in  dealing 
with  that  condition. 

Method  3. — This,  originally  recommended  by 
Lobker,  has  been  carried  out  successfully  by  Keen 
and  others  in  cases  of  division  of  the  musculo-spiral 
nerve  complicating  fractures  of  the  humerus.  It  is 
only  justifiable  in  dealing  with  injuries  of  this  nerve, 
when,  as  in  one  of  Keen\s  cases,  non-union  of  the 
bone  is  present  in  addition  to  the  nerve  injury. 

The  method  to  be  employed  to  restore  continuity 
will  depend  upon  the  nerve  injured  and  the  size 
of  the  gap.  The  method  of  election  is  undoubtedly 
auto-  or  homo-transplantation.  This  operation  is 
most  often  necessary  in  cases  of  injury  to  the  mus- 
culo-spiral nerve.  Here  the  treatment  is  simple. 
The  incision  is  j)rolonged  downwards,  the  radial 
nerve  exposed,  and  an  adequate  portion  resected 
and  sutured  Avithout  tension  into  the  gap  between 
the  two  ends  of  the  musculo-spiral  nerve,  the 
whole  being  surrounded  by  Cargile  membrane  or 
an  absorbable  tube.  The  upper  two  thirds  of  the 
radial  nerve  may  be  removed  without  causing  any 
demonstrable  effect  upon  sensation.  This  operation 
was,  I  believe,  first  suggested  and  carried  out  by  Mr. 
Dean  at  the  London  Hospital  in  1896,  but  the 
method  was  never  published.  A  portion  of  the 
patient's  own  radial  nerve,  three  inches  in  leugth,  was 
inserted  into  a  gap  in  the  musculo-spiral.     Voluntary 


NERYE    TRANSPLANTATION  97 

power  began  to  return  six  months  later,  and  wlien  I 
last  saw  liim,  five  years  after  the  operation,  recovery 
was  perfect.  A  similar  operation  may  be  carried  out 
in  the  case  of  other  nerves  of  suitable  size. 

We  do  not  yet  know  how  much  nerve  it  is  possible 
to  transplant  with  success.  Four  inches  have  been 
used  and  recovery  ensued,  but  if  the  distance  exceeds 

this  it  v/ould  probably  be  wiser  to  resort  to  anasto- 
mosis. 

But  auto-transplantation  may  be  impossible  on 
account  of  the  size  of  the  nerve — for  example,  the 
great  sciatic.  It  may  be  feasible  in  hospital  practice 
to  transplant  a  portion  of  nerve  from  an  amputated 
limb  (homo-transplantation) .  This  should  be  done  if 
possible,  with,  of  course,  every  precaution  against 
infection.  If  this  is  impracticable,  tubular  suture 
should  be  performed.  A  decalcified  bone  tube  or 
sterile  preserved  animals  artery  is  passed  over  one 
end  of  the  nerve,  and  the  ends  are  then  brought  as 
nearly  as  possible  into  apposition  by  catgut  sutures 
and  the  tube  slipped  into  position  to  cover  the 
junction. 

When  the  distance  between  the  ends  is  more  than 
about  four  inches  and  a  nerve  of  suitable  size 
and  function  is  near,  the  peripheral  end  of  the 
divided  nerve  should  be  anastomosed  to  the  neio'h- 
bouring  sound  nerve  and  the  junction  surrounded 
with  Cargile  membrane.  No  permanent  damage 
need  result  to  the  nerve  to  which  the  peripheral  end 

7 


98  INJURIES    OF    NERVES 

is  anastomosed.  It  is  possible^  as  I  pointed  out  in 
the  chapter  on  incomplete  division^  to  cut  tlirougli 
a  third  or  more  of  the  trunk  of  a  nerve  without  pro- 
ducing more  than  a  transient  paresis_,  unless  the 
nerve  be  roughly  handled  or  the  incision  divide  a 
branchy  or  infection  occur.  Gentleness  of  handling 
is  essential  in  this  as  in  all  other  operations  upon 
nerves. 

The  after-treatment  of  these  cases  of  nerve  anas- 
tomosis must  be  carefully  carried  out.  In  addition 
to  the  general  treatment  given  on  p.  73^  special 
attention  must  be  directed  during  the  return  of 
voluntary  power  to  the  training  of  the  muscles  in 
co-ordinate  movements. 

The  method  of  filling  in  a  gap  in  a  divided  nerve 
may  be  summed  up  as  follows  :  Auto-  or  homo-trans- 
plantation when  possible ;  failing  this_,  nerve  anasto- 
mosis or  tubular  suture. 


CHAPTER   VIII 

Recovery  after  Complete  Division  of  a  Nerve — "Primary  Union  " 
— Sensory  Recovery  after  complete  Division ;  three  stages — 
Motor  Recovery — Recovery  after  Primary  Suture ;  Prognosis 
— Recovery  after  Secondary  Sntiu-e  ;  "  RajDicl  Retiirn  of  Sensi- 
bility " ;  Prognosis — Complications  arising  during  the  Pro- 
gress of  Recovery — "  Trophic  "  Ulcers—  Theories  with  regard 
to  Regeneration. 

When  a  nerve  is  completely  divided  degenera- 
tion follows  in  the  whole  peripheral  end;  before  con- 
duction can  be  re-established  regeneration  must  take 
place. 

"Primary  union." — By  this  term  was  understood 
union  of  the  divided  ends  of  a  nerve  with  re-estab- 
lishment of  conduction  without  the  occurrence  of 
degeneration  in  the  peri^Dheral  end. 

Until  1839  it  was  considered  that  function  was 
restored  by  union  of  the  divided  ends  of  the  nerve 
just  in  the  same  way  as  another  tissue.  Swan,  in 
1834,  wrote  :  "  There  appears  to  be  two  modes  which 
Nature  employs  for  effecting  the  union  of  divided 
nerves,  one  by  the  effusion  of  coagulable  lymph,  the 
other  by  granulation/^  Nasse,  in  1839,  pointed  out 
that  degeneration  occurred  in  the  peripheral  end  of 
a  divided  nerve ;    but  it  was  Waller^s    classical    re- 


100  INJURIES    OF    NERVES 

searches^  publislied  in  1852^  that  gained  general 
acceptance  for  this  view. 

In  June^  1864^  two  examples  of  "primary  union" 
of  the  median  nerve  were  reported  at  medical 
societies  in  Paris.  The  first  was  a  |)atient  operated 
npon  by  Nelaton^  who  resected  a  portion  of  the 
nerve  with  a  neuroma  :  the  second^  a  case  of  acci- 
dental division  at  the  wrist,  in  which  Laugier  had 
performed  primary  suture.  Both  Avere  reported,  and 
have  since  been  quoted,  as  examples  of  primary 
union.  But  of  Nelaton^s  case,  it  is  recorded  that 
he  observed  retention  of  sensibility  before  the 
operation,  but  "  in  spite  of  his  astonishment  said 
nothing  '^  :  and  of  the  second  case,  that  tests  applied 
fifteen  days  later  revealed  the  usual  loss  of  sensibility, 
and  that  even  seventeen  months  after  the  operation 
sensibility  was  still  defective.  With  foundations  as 
slender  as  these,  other  cases  have  been  reported. 

All  recent  experiments  have  failed  to  demonstrate 
the  existence  of  primary  union,  and  the  clinical 
evidence  is  equally  negative.  Weir  Mitchell,  writing 
on  the  subject,  summed  up  well  when  he  wrote : 
"  The  evidence  offered  by  surgeons  is  too  open  to 
criticism  to  allow  of  our  admitting  that  severed 
nerves  may  unite  by  immediate  union." 

No  case  has  been  recorded  of  immediate  return  of 
function  in  paralysed  muscles,  with  absence  of  the 
development  of  the  usual  electrical  changes ;  the  early 
"  return  "  of  sensibility  means  retention  of  sensibility. 


SENSORY    RECOVERY  101 

Difficulties  surround  the  testing  of  sensation  in 
cases  of  accidental  nerve  section;  this,  together  with 
a  want  of  appreciation  of  the  distribution  of  sensibility 
to  deep  touch  and  to  prick,  gave  rise  to  the  error. 
When  every  case  of  nerve  division  is  tested  carefully 
before  as  well  as  after  suture  no  more  will  be  heard 
of  primary  union. 

Recovery  after  complete  division  of  a  nerve. — After 
division  of  a  nerve  followed  by  suture,  an  interval 
elapses  before  restoration  of  function  commences. 
This  interval  varies  somewhat  w4th  the  age  of  the 
patient,  the  nerve  injured,  the  method  of  healing  of 
the  wound  and  the  variety  of  suture,  being  as  a  rule 
more  rapid  in  the  young  and  in  cases  of  primary 
suture  and  markedly  retarded  by  inflammation. 

Sensory  recovery. — This  may  be  divided  into  three 
stages  : 

(1)  Restoration  of  protopathic  sensibility. 

(2)  Restoration  of  sensibility  to  light  touch  and 
minor  degrees  of  temperature. 

(3)  Restoration  of  the  power  of  localisation. 

In  none  of  the  cases  of  recovery  which  I  have 
watched  did  any  change  in  sensibility  take  place 
other  than  that  due  to  regeneration.  It  is  perhaps 
possible  that  improvement  in  the  power  of  appreciation 
of  a  prick  might  take  place  during  the  first  few  days 
after  suture,  owing  to  the  "  education ''  of  the  over- 
lapping fibres  from  other  nerves  subserving  proto- 
pathic sensibility.      This  was  recorded  by  Letievant, 


102  INJUEIES    OF    NERVES 

and  was  considered  by  him  to  be  due  to  the  recovery 
of  the  "  supplementary  sensibility  "  from  shock — 
"local  torpor/^  as  he  called  it.  Although  I  have 
several  times  been  able  to  examine  the  condition  of 
sensibility  within  four  hours  of  the  receipt  of  the 
injury^  I  have  not  observed  it ;  auy  loss  of  sensibility 
that  then  existed  remained  until  regeneration  com- 
menced. In  secondary  suture  performed  several 
weeks  after  the  injury^  if  any  improvement  in  sensi- 
bility has  taken  place,  freeing  and  freshening  the 
ends  of  the  nerve  always  results  in  the  loss  of 
sensibility  becoming  identical  to  that  which  was 
present  immediately  after  the  accident.  All  the 
restoration  is  due  to  reunion  with  the  central  nervous 
system  by  means  of  its  own  central  end  or  those  of 
divided  nerves  in  the  surrounding  tissues.  I  am 
therefore  opposed  to  the  statements  made  by  several 
writers  that  "  the  return  of  sensibility  in  a  mixed  or 
sensory  nerve  does  not  prove  that  the  nerve  is 
regenerating.^^  In  cases  in  which  observations  are 
taken  immediately  after  the  injury,  all  sensory 
recovery  will  be  found  to  be  due  to  regeneration  and 
union  with  the  central  nervous  system. 

At  a  period  which  varies  somewhat  with  the  age 
of  the  patient  and  the  nerve  injured,  in  uncomplicated 
cases  being  from  about  six  to  sixteen  weeks  after 
suture,  the  first  stage  of  sensory  recovery  commences. 
The  area  insensitive  to  prick  begins  to  diminish  in 
extent,  and  protopathic  stimuli  are  usually  everywhere 


SENSORY    RECOVERY  103 

appreciated  in  from  four  to  twelve  months  after 
suture.  This  is  the  first  stage  of  recovery  (Fig.  7  b). 
The  whole  of  the  aifected  portion  of  the  limb  is  now 
in  a  condition  resembling  that  of  the  intermediate  zone 
which  existed  between  the  area  of  loss  of  sensibility 
to  prick  and  the  line  bounding  the  area  of  insensibility 
to  light  touch,  but  the  response  to  all  stimuli  is  more 
intense.  All  the  stimuli  here  appreciated  have 
an  unpleasant  tingling  character,  and  the  patient 
often  complains  bitterly  of  discomfort,  and  massage 
may  have  to  be  omitted  for  a  time.  During  this 
stage  blisters  may  a^Dpear  sjDontaneously  over  the 
analgesic  area,  but  on  its  completion  all  ulcers  heal 
and  no  further  blisters  make  their  appearance. 

During  the  whole  of  the  first  stage  the  area  of 
loss  of  sensibility  to  light  touch  remains  as  extensive 
and  as  well  defined  as  immediately  after  the  injury. 
Gradually  its  proximal  border  becomes  indefinite 
and  the  area  slowly  diminishes  in  extent  until,  at 
a  time  varying  from  about  twelve  months  in  the 
case  of  primary  suture  of  a  nerve  at  the  wrist,  to 
about  eighteen  months  after  secondary  suture  of  a 
similar  nerve,  the  whole  of  the  affected  portion  is 
sensitive  to  light  touch  and  the  iutermediate 
degrees  of  temperature.  This  concludes  the  second 
stage. 

The  interval  between  the  end  of  the  first  and  the 
beginning  of  the  second  stage  varies  with  the  variety 
of  suture  and  the  distance  from  the  periphery  of  the 


Fig.  7. 


SENSORY    RECOVERY  105 

point  of  section.  After  division  of  the  median  or 
ulnar  nerves  at  the  wrist^  followed  by  primary  suture^ 
an  interval  of  more  than  about  six  weeks  is  unusual 
unless  suppuration  has  occurred_,  and  in  favourable 
cases  in  Avhicli  the  after-treatment  by  massage  and 
stimulation  w4th  interrupted  and  constant  currents 
has  been  faithfully  carried  out  there  may  be  no 
appreciable  interval.  But  if  the  wound  suppurated, 
or  secondary  suture  has  been  performed,  the  hand 
may  remain  in  this  stage  for  a  considerable  period 
of  time  and  recovery  may  be  permanently  arrested. 

It  has  long  been  the  teaching  that  the  distance 
from  the  periphery  at  which  a  nerve  is  divided 
affects  the  time  necessary  for  the  commencement  of 
recovery — that  the  nearer  the  periphery  the  seat  of 
suture,  the  earlier  the  recovery.  Taking  recovery 
as  a  whole,  this  is  in  accordance  with  my  experience, 
but  it  does  not  apply  to  the  commencement  of  the 
first  stage  of  sensory  recovery.  The  distance  from 
the  periphery  at  wdiicli  a  nerve  is  divided  doesnot  affect 
the  time  necessary  for  the  commencement  of  the  first 
stage  of  recovery,  yet  it  markedl}^  prolongs  the  interval 
bfetween  the  end  of  the  first  and  the  beginning  of 
the  second  stage,  and  final  recovery  is  much  delayed. 


Fig.  7. — To  illustrate  the  method  of  recovery  after  com- 
plete division  of  a  peripheral  nerve,  a.  Loss  of  sensibility 
resulting-  from  division  of  ulnar  nerve,  b.  Termination  of 
first  stage  of  recovery,  sensitive  to  protopathic  stimiili, 
insensitive  to  light  touch,  c.  Termination  of  second 
stage.     Dotted  line  represents  line  of  change. 


106  INJURIES    OF    NERVES 

A  comparison  of  tlie  following  two  cases  will 
illustrate  this  : 

"  A  boy  suffered  division  of  liis  ulnar  nerve  at 
the  elbow  ;  seventeen  weeks  after  primary  suture 
sensibility  to  prick  began  to  be  restored^  but  sensi- 
bility to  light  touch  showed  no  sign  of  recovery 
until  forty-one  weeks  after  suture_,  and  was  not 
completely  restored  until  seventy-five  weeks  after 
suture." 

"  In  an  adult  patient  in  whom  the  ulnar  nerve 
had  been  divided  at  the  wrist,  sensibility  to  prick 
began  to  be  restored  nineteen  weeks  after  primary 
suture,  to  light  touch  in  twenty-five  weeks,  and  the 
latter  was  appreciated  over  the  whole  affected  portion 
of  the  hand  forty  weeks  after  suture." 

The  method  of  recovery  following  the  grafting  of 
the  whole  thickness  of  the  skin  also  confirms  this 
opinion.  In  a  boy,  aged  fourteen  years,  on  whom  I 
performed  Wolfe^s  grafting  for  contraction  of  the 
middle  finger,  the  graft  healed  by  first  intention. 
At  the  first  dressing,  ten  days  after  operation,  he 
was  able  to  appreciate  pressure  at  the  periphery  of 
the  graft ;  thirty  days  after  operation  he  was  able  to 
distinguish  between  the  head  and  the  point  of  a  pin 
everywhere  over  the  graft,  and  could  discriminate 
accurately  between  ice  and  water  at  50  C,  but  was 
entirely  insensible  to  light  touch.  Three  weeks  later 
all  forms  of  sensibility  were  restored  and  the  discrimin- 
ation of  two  points  was  perfect  at  one  centimetre. 


SENSORY    RECOVERY  107 

In  this  patient  the  commencement  of  the  restora- 
tion of  sensibility  to  prick  occurred  at  the  same  time 
as  after  some  cases  of  division  of  a  nerve  at  the  wrist, 
but  the  interval  between  the  end  of  the  first  and  the 
beginning  of  the  second  stage  was  not  marked,  and 
the  time  necessary  for  the  complete  restoration  of 
sensation  was  shorter  by  many  months.  In  several 
similar  cases  I  have  observed  the  same  method  of 
recovery. 

But  after  the  restoration  of  sensibility  to  light 
touch  and  the  minor  degrees  of  temperature  the 
sensibility  of  the  part  is  by  no  means  perfect.  If 
a  sharp  point  be  dragged  across  the  skin  from 
normal  to  affected  parts,  sensation  is  found  to 
change  as  soon  as  the  old  boundary  for  the  loss  of 
light  touch  is  reached.  At  this  line  the  stimulus 
seems  to  become  more  diffuse  ;  patients  say  that  it 
tingles,  or  it  seems  to  be  more  uncomfortable  and 
often  withdraw  the  part.  While  this  area  of 
changed  sensibility  is  jDresent  the  discrimination  of 
two  points  (the  compass  test)  is  always  defective. 
Improvement  in  the  power  of  accurate  localisation 
constitutes  the  third  stage  of  recovery.  No  sensory 
recovery  should  be  recorded  as  perfect  unless  the 
appreciation  of  the  compass  test  is  as  good  as  on  the 
sound  side.  Until  this  has  taken  place  the  part  is 
useless  for  delicate  work,  and  after  division  of  one 
of  the  nerves  of  the  hand  all  work  requiring  skilled 
use  of  the  hand  is  impossible. 


108  INJURIES    OF    NERVES 

Tlie  time  necessary  for  perfect  recovery  varies^ 
and  will  be  discussed  more  fully  under  primary  and 
secondary  suture. 

The  observations  wliicli  it  lias  been  possible  to 
make  ujDon  tlie  recovery  of  deep  sensibility  have 
been  too  few  to  enable  rules  to  be  laid  down.  The 
extent  of  the  loss  and  the  rapidity  of  recovery  depend 
in  many  instances  upon  the  division  of  structures 
other  than  nerves ;  but  in  those  cases  in  which  deep 
touch  was  lost  as  the  result  of  the  division  of  nerves 
alone  it  was  restored  before  the  restoration  of  sensi- 
bility to  prick. 

Moto7'  recovery.' — At  a  time  varying  with  the 
distance  of  the  point  of  suture  from  the  periphery 
and  the  age  of  the  |)atient_,  the  muscles  regain  their 
voluntary  power.  This  return  is  usually  preceded 
by  a  change  in  the  electrical  reactions  of  the  affected 
muscles  :  the  contraction  given  to  stimulation  with 
the  constant  current  loses  its  sluggish  character_,  and 
is  obtained  with  a  current  smaller  than  is  necessary 
to  produce  a  contraction  in  the  corresponding  muscles 
of  the  sound  side^  and  polar  reversal  disappears  ; 
the  reactions  become  identical  with  those  I  have 
described  as  typical  of  incomplete  division.  Dr. 
Head  and  the  author  found  that  irritability  to  the 
interrupted  current  is  usually  present  on  the  same 
date  as  the  first  return  of  voluntary  power  is  noticed. 
Recovery  after  primary  suture. — The  following  con- 
clusions are  based  upon  the  personal  observation  of 


RECOVERY  AFTER  PRIMARY  SUTURE   109 

over  fifty  cases  of  primary  suture.  In  none  of  these 
did  any  early  return  of  sensibility  take' place.  The 
earliest  date  at  which  the  first  return  of  sensibility 
to  prick  was  noticed  was  5  Aveeks,  the  latest  25 
weeks^  and  the  first  stage  was  comjDlete  in  from  23 
to  46  weeks.  The  second  stage  commenced  in  from 
19  to  46  weeks.  The  great  prolongation  observed  in 
some  cases  was  due  to  suppuration — difficult  to  avoid 
in  many  cases  of  accidental  wounds. 

Restoration  of  localisation  was  not^  as  a  rule, 
complete  until  more  than  two  years  after  suture,  and 
often  yet  longer  time  was  necessary. 

After  primary  suture  of  one  of  the  nerves  of  the 
hand,  no  matter  at  what  level,  restoration  of 
sensibility  to  prick  will  commence  in  from  six  weeks 
to  four  months,  and  will  be  appreciated  over  the 
whole  of  the  affected  area  in  from  four  to  six  months  ; 
the  end  of  the  second  stage  of  recovery  will  be 
reached  in  about  a  year. 

It  has  long  been  the  usual  teaching  that  the 
further  the  point  of  section  from  the  periphery,  the 
longer  the  time  necessary  for  motor  return.  The 
unique  series  of  cases  of  division  of  the  brachial 
plexus  recorded  by  Etzold  proved  this  :  in  all,  the 
muscles  nearest  the  seat  of  the  lesion  first  regained 
voluntary  power.  I  have  been  able  to  confirm  these 
observations  after  division  of  nerves  in  both  the 
upper  and  lower  limbs.  It  is  well  illustrated  after 
division  of  the  ulnar  nerve.     After  primary  suture  of 


110  INJURIES    OF    NERVES 

this  nerve  at  the  wrist^  motor  power  returns  in  about 
a  year ;  but  if  divided  at  the  elbow,  nearly  two  years 
elapse  before  the  intrinsic  muscles  of  the  hand  are 
capable  of  voluntary  movement^  although  the  flexor 
carpi  ulnaris  recovers  at  a  much  earlier  date. 

The  rule  can  be  laid  down  that  after  the  usual 
division  of  nerves  at  the  wrist  motor  power  will  be 
regained  in  a  year  ;  if  at  the  elbow^  motor  power 
will  not  return  to  the  muscles  of  the  hand  for  two 
years. 

Prognosis  after  primary  suture. — By  complete  re- 
covery is  understood  the  restoration  of  perfect  appre- 
ciation of  all  sensory  stimuli  and  the  return  not  only 
of  voluntary  power  to  the  aifected  muscles,  but  of 
perfect  function  ;  in  other  words,  the  part  must  regain 
a  condition  indistinguishable  from  the  normal. 

This  may  occur  after  primar}^  suture. 

The  completeness  of  the  recovery  will  depend  to  a 
large  extent,  as  already  pointed  out,  upon  the  care 
taken  in  the  after-treatment :  but  some  recovery  is 
to  be  expected  in  all  cases,  no  matter  how  neglectful 
the  patient  may  be.  In  every  case  of  primary 
suture  which  I  have  watched,  motor  power  was  re- 
gained and  the  second  stage  of  recovery  of  sensibility 
completed.  All  cases  uncomplicated  by  suppuration 
which  I  was  able  to  keep  under  observation  for  a 
sufficiently  long  period,  regained  perfect  sensation. 

I   also    investigated    the  condition  of  as  many   as 
possible  of  the   older  cases    of  primary  suture   per- 


PROGNOSIS  OF  PRIMARY  SUTURE     111 

formed  at  tlie  London  Hospital^  and  found  that  there 
was  only  one  in  which  no  improvement  took  place — a 
patient  in  whom  the  wound  was  infected,  leading  to 
a  cellulitis  which  necessitated  many  incisions. 

The  prognosis  will  depend  to  a  certain  extent 
upon  the  nerve  injured,  the  distance  of  this  injury 
from  the  periphery,  and  the  condition  of  the  wound. 
For  example,  the  musculo-spiral  nerve  in  the  lower 
third  of  the  arm  carries  no  exclusive  sensory  supply 
to  any  part  of  the  forearm  or  hand,  and  the  muscles 
it  supplies  are  not  so  intimately  connected  with 
delicate  movements  of  the  fingers  as,  for  instance, 
those  supplied  by  the  ulnar ;  complete  recovery  will 
therefore  be  reached  more  quickly  and  in  a  greater 
proportion  of  cases.  The  further  the  seat  of  section 
from  the  periphery,  the  longer  the  period  of  necessary 
after-treatment  and  the  greater  the  chance  of  the 
accidents  which  hinder  complete  recovery. 

After  primary  suture  of  one  of  the  nerves  of  the 
forearm  uncomplicated  by  suppuration,  recovery  will 
ensue  and  become  perfect  if  appropriate  after-treat- 
ment is  carried  out.  Muscular  power  and  irritability 
to  the  interrupted  current  will  be  restored  in  from 
nine  months  according  to  the  level  of  the  lesion,  but 
three  years  will  probably  be  necessary  to  complete 
sensory  recovery, 

I*^'  Recovery  after  secondary  sutui^e. — From  time  to  time 
instances  of  rapid  restoration  of  sensibility  after  this 
variety    of   suture   have   been   recorded.      Of   recent 


112  INJURIES    OF    NERVES 

observers  Kennedy  is  the  strongest  supporter  of  this 
possibility.  In  some  of  the  cases  the  sensation 
restored  at  an  early  date  again  became  lost. 

Experimental  work  does  not  throw  any  light  upon 
these  records.  Head  and  Ham  have  shown  in  their 
experimental  work  on  cats^  that  after  secondary 
suture  of  a  nerve  which  had  been  divided  for  at 
least  two  months  and  consisted  of  elongated  cells, 
twenty-eight  days  elapsed  before  it  would  conduct 
impulses.  This  agrees  with  the  earliest  time  of 
return  that  I  have  noted  in  clinical  work.  In  none 
of  my  twenty-one  cases,  in  which  the  suture  was 
performed  in  patients  of  various  ages,  and  from  four 
weeks  to  five  years  after  division,  was  any  restoration 
of  sensibility  noticed  before  the  thirtieth  day, 
although  carefully  looked  for.  Professor  Halliburton, 
speaking  on  the  subject,  suggested  that  what  I  have 
already  mentioned  as  one  of  the  causes  of  the  so-called 
"  primary  union,^^  the  presence  of  deep  sensibility, 
has  led  to  similar  error  here.  This  is  undoubtedly 
the  explanation  of  most  of  these  cases.  My  attention 
has  more  than  once  been  drawn  by  Hospital  Residents 
to  the  ^'  rapid  return  "  of  "  sensibility  to  prick,^^  after 
secondary  suture,  which,  on  careful  testing  in  the 
usual  manner,  proved  to  be  deep  sensibility.  In  one 
patient  upon  whom  I  had  performed  secondary  suture 
of  the  median  nerve  it  was  said  that  sensibility  to 
prick  had  returned  on  the  day  following  operation. 
On  testing,  I   found  that  he  complained  of  pain  on 


RECOVERY  AFTER  SECONDARY  SUTURE  113 

pressure^  but  could  not  distinguish  tlie  sharpness  of 
the  point  of  a  pin  ;  it  was  equally  painful  and  pro- 
duced the  same  sensation  as  pressure  with  the  blunt 
end  of  a  pencil ;  moreover,  he  was  entirely  insensitive 
to  the  painful  interruj^ted  current,  and  all  temperature 
appreciation  was  absent.  There  was  no  doubt  that 
the  pain  was  that  caused  by  deep  pressure,  which 
could  be  readily  evoked  before  operation. 

Before  concluding  that  a  rapid  return  of  sensi- 
bility has  taken  place  in  any  patient,  sensibility  must 
be  carefully  tested  in  all  forms  and  mapped  out  on 
charts  before  and  after  suture,  at  first  day  by  day, 
later  week  by  week,  up  to  recovery.  It  is  evident, 
however,  that  a  rapid  return  of  sensibility  is  not  to 
be  expected  after  secondary  suture,  and  that  its 
"  occurrence  "  must  be  regarded  as  unusual. 

Recovery  after  secondary  suture  follows  the  same 
general  lines  as  after  primary.  But  much  greater 
variability  obtains  in  the  time  at  which  the  various 
stages  of  sensory  recovery  begin.  Motor  recovery 
follows  t'he  same  march  as  after  primary  suture. 

But  although  motor  and  sensory  recovery  follow 
the  same  stages  as  after  primary  suture,  their  time 
of  commencement  differs.  The  time  necessary  for 
the  commencement  of  the  first  stage  of  sensory 
recovery  may  be  shorter  than  after  primary  suture, 
the  changes  in  the  peripheral  end  necessary  to 
regeneration  of  the  nerve  being  advanced  at  the 
time  of  suture.      But  usually  the  time  is  much  longer 

8 


114  INJURIES    OF    NERVES 

and  tlie  interval  between  suture  and  the  commence- 
ment of  tlie  second  stage  of  recovery  almost  double 
as  long.  So  far  I  liave  not  yet  seen  complete 
sensory  recovery  follow  secondary  suture^  altliougii  I 
have  watched  patients  for  more  than  five  years  and 
seen  them  at  intervals  up  to  fifteen  years  after 
suture  ;  in  all  the  patients  some  difference  could  be 
appreciated  between  the  two  limbs^  an  area  of 
changed  sensibility  remaining  with  imperfect  appre- 
ciation of  the  compass  test.  This  may  be  of  no 
moment  after  suture  of  the  musculo-spiral  or  external 
popliteal  nerves^  but  it  materially  affects  the  result 
of  secondary  suture  of  the  median  or  ulnar. 

Much  less  variation  occurs  with  regard  to  motor 
recovery,  but  the  time  necessary  is  almost  always 
longer. 

Prognosis  after  secondary  suture. — The  first  question 
that  arises  is,  how  long  after  the  injury  is  it  possible 
to  perform  secondary   suture  with  any  hope  of  suc- 
cess ;    unfortunately  it   is    one  to  which  no   definite 
answer  can  at  present  be  given.     Although  instances 
of   "  successful "  operations  have   been    recorded  at 
intervals    up    to    fifteen    years    after     division,    the 
reports    are   so   meagre   that   no  conclusions   can  be 
drawn    from    them.      But    an    interesting   series    of 
cases  has  been  recorded  by  Bowlby.      In  these,  suture 
was  performed  at  times  ranging  from  twelve  years 
after   division   downwards.       He    came   to   the    con- 
clusion that  muscular  recovery  was  not  likely  to  be 


PROaNOSIS  OF  SECONDARY  SUTURE    115 

marked  if  operation  was  delayed  longer  than  two 
years,  and  that  no  instance  of  perfect  motor  recovery 
had  been  reported  after  four  years. 

Varied  statements  have  been  made  respecting  the 
injSuence  upon  recovery,  exercised  by  the  interval 
between  division  and  suture.  Howell  and  Huber, 
from  a  study  of  recorded  cases,  wrote  :  ''  In  general 
the  prognosis  is  better  and  the  time  of  recovery 
shorter  the  sooner  after  the  injury  the  nerve  is 
sutured/^  Kennedy  considers  it  of  great  importance  ; 
he  writes  :  "  Nothing  can  be  of  more  importance  in 
giving  a  prognosis  than  the  interval  between  the 
operation  and  the  accident.  If  this  interval  is  within 
three  or  four  months  recovery  may  be  expected,  but 
if  it  extends  to  almost  a  year,  recovery  of  muscles  is 
unlikely." 

Wide  variations  occur,  as  I  have  already  stated,  in 
the  time  at  which  the  various  stages  of  recovery 
commence  and  are  completed,  but  they  ajopear  to 
bear  no  relation  to  the  time  which  has  elapsed  be- 
tween the  injury  and  operation,  but  often  have  a 
close  connection  with  the  method  of  healiuG*  of  the 
accidental  wound ;  suppuration  retards  the  time  at 
which  the  first  stage  of  recovery  commences.  For 
example,  I  performed  secondary  suture  of  the  median 
nerve  nine  weeks  after  division ;  sensory  recovery 
did  not  commence  for  twenty-four  weeks  and  was 
not  complete  in  116;  the  muscles  did  not  act 
voluntarily  until  nearly  two  years   after  suture.      In 


116  INJURIES    OF    NERVES 

anotlier  patient  of  about  tlie  same  age,  in  whom  the 
median  nerve  was  divided  at  the  same  level,  ninety- 
five  weeks  elapsed  between  the  injury  and  operation, 
and  yet  sensory  recovery  commenced  on  the  thirtieth 
day,  and  motor  at  the  thirtieth  week.  Both  opera- 
tion wounds  healed  by  first  intention,  but  in  the 
former  case  the  original  accidental  wound  had  suppu- 
rated severely,  in  the  latter  the  nerve  was  severed 
through  a  small  punctured  wound  w^hich  healed  by 
first  intention. 

My  experience  coincides  with  Bowlby^s  that  the 
interval  between  the  date  of  suture  and  the  date  of 
restoration  of  sensation  and  motion  is  irregular,  and 
bears  no  direct  relation  to  the  length  of  time  which 
has  elapsed  since  the  injury  in  cases  where  the 
operation  has  not  been  delayed  for  as  much  as  three 
years. 

Out  of  twenty-one  cases  of  secondary  suture  which 
I  have  had  under  observation,  in  whom  the  interval 
between  injury  and  operation  was  less  than  three 
years,  some  motor  recovery  ensued  in  all,  but  in 
none  did  perfect  sensory  recovery  take  place. 

The  prognosis  of  secondary  suture  depends  not 
only  upon  the  time  after  injury  (after  three  years), 
but  also,  to  a  certain  extent,  upon  the  nerve  injured, 
for  example,  recovery  may  be  expected  to  become 
perfect  after  secondary  suture  of  the  musculo-spiral, 
but  is  unlikely  to  become  so  after  secondary  suture 
of  the  median  or  ulnar. 


PROGNOSIS  OF  SECONDARY  SUTURE  117 

Before  giving  an  opinion  as  to  the  advisability  of 
operation  otlier  factors  have  to  be  taken  into  con- 
sideration :  the  condition  of  the  paralysed  muscles 
as  regards  their  reaction  to  the  constant  current^  the 
amount  of  atrophy  and  overstretching  present  and 
the  contracture  in  the  opposing  muscles.  If  great 
atropliy  of  the  part  and  deformity  has  resulted  from 
the  nerve  injury,  complete  recovery  of  function  is 
impossible,  although  the  muscles  may  regain  the 
power  of  voluntary  movement. 

In  all  cases  sensory  recovery  up  to  the  end  of  the 
first  stage  is  to  be  expected;  this  is  important,  as 
recovery  up  to  this  stage  abolishes  the  tendency  to 
the  formation  of  ulcers.  Recovery  of  motor  power 
after  long  ^Deriods  is  unlikely,  for  not  only  have 
changes  taken  place  in  the  muscles  themselves  and 
in  their  opponents  which  render  recovery  unlikely, 
but  also  in  the  central  nervous  system ;  it  is  probable 
that  in  patients  in  whom  the  nerve  has  been  divided 
for  a  long  period  and  the  muscles  retain  their  irrita- 
bility to  the  constant  current,  nerve  anastomosis  is 
more  likely  to  be  successful  than  secondary  suture. 

In  conclusion,  recovery,  both  sensory  and  motor, 
will  take  longer  after  secondary  than  after  primary 
suture.  Up  to  three  j^ears  from  the  accident 
muscular  recovery  will  probably  ensue.  Whether  it 
will  become  perfect  depends  to  a  great  extent  upon 
the  amount  of  deformity  that  has  taken  place,  but  it 
may  be  complete;  perfect  sensory  recovery  is  unlikely. 


118  INJURIES    OF    JSTERYES 

Complications  arising  during  recovery. — Complications 
may  arise  during  tlie  progress  of  recovery.  Pain  is, 
as  a  rule,  present  in  tlie  distribution  of  the  affected 
nerve  during  the  first  two  or  three  days  after  suture ; 
this  is  due  to  irritation  of  the  central  end  and  is 
rarely  of  sufficient  degree  to  need  treatment.  If 
severe  it  points  to  an  infective  neuritis.  The  wound 
should  be  inspected,  and,  if  necessary,  opened  up  and 
drained.  If  this  has  been  done,  the  condition  of  the 
nerve  should  be  explored  at  a  later  period  when  the 
wound  has  soundly  healed.  In  cases  in  which  sup- 
puration has  taken  place  gradual  deterioration  of 
function  may  occur  after  a  period  of  improvement, 
due  to  involvement  of  the  junction  in  fibrous  tissue  ; 
this  usuall}^  arises  after  silk  has  been  used  as  a 
suture. 

Blisters  may  arise  at  two  periods  during  the 
stage  of  recovery  after  complete  division  and  suture. 
Slight  injuries  pass  unnoticed  during  the  stage  of 
complete  insensibility  to  cutaneous  stimuli;  the  patient 
not  infrequently  burns  himself,  or,  if  engaged  in 
manual  labour,  injures  the  limb  while  at  work.  To 
this  group  belong  the  so-called  perforating  ulcers 
seen  after  division  of  the  great  sciatic  nerve.  The 
ulcers  so  arising  heal  readily  with  appropriate  treat- 
ment. With  the  first  sign  of  returning  sensibility 
to  prick  the  patient  often  complains  of  pain  shooting 
into  the  affected  part,  and  blisters  may  arise  spon- 
taneously.     These  may  burst,  leaving  a  raw  surface, 


REGENERATION  119 

which^  if  infected^  becomes  an  ulcer.  If  protected 
they  dry^  leaving  a  scab  under  which  new  epithelium 
forms. 

All  tendency  to  the  formation  of  blisters  ceases 
with  the  restoration  of  sensibility  to  prick.  The 
immunity  experienced  on  the  restoration  of  this  form 
of  sensibility  is  often  striking ;  in  spite  of  work  con- 
tinued under  unaltered  conditions  no  further  trouble 
arises.  Thus^  a  carpenter  whose  median  and  ulnar 
nerves  had  been  accidentally  divided  suffered^  both 
before  and  after  secondary  suture^  from  ulcers  caused 
by  burns  or  blisters  from  the  use  of  his  tools.  On 
the  complete  return  of  protopathic  sensibility,  eight 
months  after  suture^  all  the  ulcers  healed  and  no 
more  appeared. 

The  distribution  of  these  ulcers  is  further  proof  of 
the  close  association  which  exists  between  protopathic 
sensibility  and  the  nutrition  of  the  skin.  Under  no 
circumstances^  except  when  complicated  by  acute 
sepsis^  do  they  extend  beyond  the  area  of  insensi- 
bility to  prick. 

Theoretical  consideration  with  regard  to  regeneration. 
— Much  attention  has  recently  been  directed  to  the 
method  of  regeneration^  and  it  will  be  necessary  to 
discuss  this  briefly,  together  with  the  light  thrown 
upon  it  by  the  clinical  experience  of  recovery. 

Investigators  are  divided  into  two  schools — the 
central  and  the  peripheral.  The  former,  following 
Waller,   believe    that    regeneration    consists    in    the 


120  INJURIES    OF    NEEYES 

downgrowtli  of  axis  cylinders  from  the  central  end 
of  the  nerve  into  the  nerve  sheaths  of  the  peripheral 
end  destitute  of  axis  cylinders ;  the  latter_,  who 
consider  that  the  new  axis  C3''linders  are  formed  in 
the  peripheral  end  from  the  cells  of  the  nucleated 
sheath.  Prominent  authors  are  ranged  on  the  two 
sides  :  Mott_,  Halliburton^  Langley  and  Anderson  are 
strong  supporters  of  the  central  theory^  while 
BallancC;  and  Purves  Stewart^  Kennedy  and  Bethe  are 
prominent  upholders  of  the  peripheral  doctrine. 

All  recent  writers^  however^  are  agreed  up  to  a 
certain  point ;  at  a  time  after  division  of  a  nerve^ 
varying  with  the  animal  used  and  its  age^  whether 
union  Avith  the  central  nervous  system  has  taken 
place  or  not^  proliferation  of  the  neurilemma  cells 
leads  to  the  formation  of  a  strand  of  spindle-shaped 
cells^  called  by  different  observers^  "  embrj'-onic 
fibres/^  ^'' band  fibres/^  or  "  neuroplastic  fibres. ^^  It 
is  with  regard  to  the  further  changes  which  take 
place  in  the  peripheral  end  of  a  nerve  separated  from 
its  central  end  that  opinion  is  so  greatly  divided. 
Ballance  and  Purves  Stewart^  Langley  and  Anderson^ 
Bethe  and  others  have  found  axis  cylinders  clothed 
with  medulla.  Some  of  these  observers  considered 
this  as  evidence  of  autogenetic  regeneration,  but 
Langley  and  Anderson  showed  that  the  formation  of 
medullated  axis  cylinders  in  the  peripheral  end  of  a 
nerve  separated  from  its  own  central  end  was  due  to 
union  with  the  central  nervous  system  by  means  of 


REGENERATION  121 

divided  nerves  in  the  tissues  around.  They  found 
that  all  the  meduUated  fibres  in  the  peripheral  end 
degenerated  when  the  nerves  which  run  to  the  tissues 
near  the  cut  end  were  divided  near  the  spinal  cord. 
These  experiments  appear  to  be  conclusive^  and  to 
account  for  the  varying  results  obtained. 

It  appears  certain  that  no  new  axis  cylinders  are 
formed  in  the  peripheral  end  of  a  divided  nerve  until 
it  ao'ain  comes  into  connexion  with  the  central 
nervous  system^  through  its  own  central  end  or 
through  the  central  ends  of  small  divided  nerves  in 
the  tissues  around.  But  it  seems  probable  that 
after  suture^  regeneration  of;,  at  least^,  the  fibres  sub- 
serving protopathic  sensibility  takes  place  peripher- 
ally. This  is  in  accordance  with  the  results  given 
by  the  study  of  sensory  recovery  after  primary  and 
secondary  suture.  The  first  stage  of  recovery  com- 
mences at  about  the  same  time^  no  matter  at  what 
level  th&  nerve  is  divided.  But  the  clinical  evidence 
is  not  so  clear  with  regard  to  the  fibres  which  sub- 
serve sensibility  to  light  touch  and  those  which 
supply  the  muscles.  I  have  shown  that  the  first 
signs  of  recovery  of  sensibility  to  light  touch  and  of 
voluntary  power  hi  the  affected  muscles  are  noticed 
at  a  later  date  the  farther  from  the  periphery  the 
nerve  is  divided.  But  as  the  same  occurs  during 
the  recovery  of  a  nerve  from  the  effects  of  pressure 
when  no  regeneration  is  necessary,  the  explanation 
given  by  Henriksen  seems  to  be  correct:  "The  injured 


122  INJURIES    OF    NERVES 

nerve  is  a  bad  conductor ;  tlie  longer  the  piece  of 
nerve  injured  the  greater  the  resistance 
and  thus  a  higher  degree  of  regeneration  must  be 
supposed  before  it  can  be  expected  that  an  impulse 
will  cause  movement.  ...  It  cannot  be  taken 
as  evidence  that  the  nerve  is  growing  from  the 
centre. ^^ 

In  conclusion^  it  appears  that  the  clinical  evidence^ 
so  far  as  it  is  positive,  is  in  favour  of  the  formation  of 
new  axis  cylinders  in  situ,  and  that  even  when  it  is 
negative  it  discloses  nothing  against  this  theory. 
But  union  with  the  central  nervous  system  is  necessary 
before  the  development  of  axis  cylinders  takes  place. 
Taken  with  the  experimental  CAddence,  it  goes  to 
show  that  regeneration,  at  any  rate  of  the  fibres  sub- 
serving protopathic  sensibility,  is  peripheral  but  not 
autogenetic. 


CHAPTER   IX 

Eecovery  after  Incomplete  Division  of  a  Nerve — Sensory  Recovery, 
Illnstrative  Cases — Motor  Eecovery — Prognosis. 

Aftee  incomplete  division  of  a  mixed  nerve  tlie 
loss  of  sensation  and  motion  may  at  first  resemble 
that  which  follows  complete  division^  but  the  method 
of  recovery  is  entirely  different. 

After  complete  division  of  a  nerve  and  sntnre, 
sensibility  to  prick  becomes  everywhere  restored 
before  the  commencement  of  the  recovery  of  sensi- 
bility to  light  touch.  There  is  thus  an  interval  before 
the  commencement  of  the  second  stage  of  recovery 
(restoi-ation  of  sensibility  to  light  touch)  in  which 
the  whole  affected  area  is  sensitive  to  protopathic 
but  insensitive  to  epicritic  stimuli.  Complete  sensory 
recovery^  the  disappearance  of  the  area  of  changed 
sensibility  to  prick^  and  the  perfect  restoration  of 
sensibility  to  the  compass  test  often  occupies  several 
years. 

But  after  incomplete  division  sensibility  to  light 
touch  and  to  prick  are  restored  together  (vide  Figs. 
8  A,  B;  c),  and,  unless  nerve-fibres  have  been  ana- 
tomically divided  in  considerable  number  the  power 


124  INJURIES    OF    NERVES 

of  appreciating  two  points  (the  compass  test)  is  soon 
regained. 

Knowledge  of  this  method  of  sensory  recovery, 
first  described  by  Dr.  Head  and  the  author,  is  a 
valuable  addition  to  our  powers  of  diagnosis.  If 
both  forms  of  sensibility  are  recovering  together,  it 
is  certain  that  the  injury  has  not  been  severe  enough 
to  produce  complete  interruption  of  conduction  in  the 
injured  nerve,  with  degeneration  of  the  whole  peri- 
pheral end. 

The  following  cases  illustrate  this  method  of  re- 
covery : 

"  A  man,  aged  twenty-seven  years,  cut  his  left 
wrist  Avith  a  fragment  of  broken  glass,  September 
20th,  1902.  When  I  saw  him  two  and  a  half  hours 
later  a  small  incised  wound  was  present  over  the 
position  of  the  median  nerve  at  the  wrist.  The 
abductor  and .  opponens  pollicis  muscles  acted 
perfectly,  but  sensibility  was  lost  over  the  area 
shown  in  Fig.  8  a.  Protopathic  sensibility  was 
lost  over  an  area  somewhat  smaller  than  usual 
after  complete  division  of  a  median  nerve  with 
such  a  large  exclusive  supply — that  is,  the  loss 
of  sensibility  to  prick  did  not  involve  the  radial 
border  of  the  index  finger  or  the  palmar  surface  of 
the  thumb,  although,   an  extensive  area  on  the  palm 

Fig.  8. — To  show  method  of  recovery  after  incomplete 
division  of  a  nerve,  a.  Loss  of  sensibility  after  incom- 
plete division  of  the  median  nerve,  b  and  c.  Stages  in  the 
recovery  of  both  forms  of  sensibility  together.  Dotted 
areas  represent  ill-defined  limits. 


Fig.  8. 


126  mJURIES    OF    NERVES 

was  affected.  The  loss  of  sensibility  to  light  touch 
was  as  widespread  and  as  well  defined  as  after  com- 
plete division.  I  explored  the  wound  at  once^  and 
found  the  median  nerve  for  half  an  inch  immediately 
above  the  annular  ligament  dark  red  in  colour  and 
swollen^  with  a  superficial  incised  wound  on  its  ulnar 
side, 

No  change  in  the  condition  of  sensibility  took 
place  until  six  days  later^  but  the  muscles  lost  their 
irritability  to  the  interrupted  current^  although  they 
retained  the  joower  of  voluntary  movement.  Four- 
teen days  after  operation  the  area  of  loss  of  both 
forms  of  sensibility  began  to  diminish  in  extent  from 
above  downwards  (Fig.  8  b).  Over  the  previously 
insensitive  portion  of  the  palm  the  compass  test  was 
almost  perfect  at  1  cm.^  and  was  completely  restored 
in  this  position  fourteen  days  later.  Three  months 
after  the  injury  the  muscles  again  reacted  to  the 
interrupted  current.  In  six  months  the  condition  of 
sensibility  was  as  shown  in  Fig.  8  c ;  in  nine  months 
it  was  perfect^  exce^ot  over  the  terminal  phalanges  of 
middle  and  ring  fingers.^^ 

A  similar  method  of  recovery  is  shown  in  Fig. 
9  A,  B^  taken  from  a  patient  with  an  incomplete 
division  of  ulnar  nerve. 

"  This  patient  sustained  a  fracture  of  radius  and 
ulna  in  the  lower  third  of  the  forearm  eight  weeks 
before  I  saw  him.  On  examination  on  January  1st, 
1906,  sensibility  was  lost  over  the  area  in  Fig.  9  a. 


INCOMPLETE    DIVISION:     RECOVERY     127 

All  the  muscles  in  the  hand  supplied  by  the  ulnar 
nerve  were  paralysed  and  gave  the  reactions  typical 
of  incomplete  division. 

"  On  January  ord  I   explored  the  condition  of  the 


Fig.  9. — a.  To  illustrate  the  loss  of  sensibility  followiurr 
incomplete  division  of  the  nlnar  nerve,  b.  Method  of 
recovery,  both  forms  of  sensibility  together. 

nerve.  I  found  it  bound  down  to  the  ulna  through 
the  fibres  of  the  flexor  profundus  digitorum ;  on 
freeing  it  there  were  signs  on  its  posterior   surface 


128  INJURIES    OF    NERYBS 

that  it  had  been  wounded  by  one  of  the  fractured 
ends  of  the  bone. 

^'  Ten  days  later  both  forms  of  sensibility  began  to 
return  together^  and  six  weeks  after  the  operation 
the  condition  of  sensibility  was  as  shown  in  Fig.  9  b." 

Recovery  after  a  less  severe  form  of  injury  is 
illustrated  by  the  following  case  : 

"A  patient  was  kicked  at  football  over  the  inner 
condyle  of  the  humerus.  As  a  result  sensibility  to 
light  touch  was  lost  over  an  area  on  the  palm  of  the 
hand  corresponding  almost  to  the  distribution  of  the 
palmar  branch  of  the  nerve  ;  protopathic  sensibility 
was  lost  over  an  area  almost  as  extensive.  All  the 
movements  of  the  fingers  could  be  performed^  but 
the  little  finger  was  weak  and  tended  to  assume  the 
ulnar  position  ;  all  reacted  to  the  interrupted  current. 
Both  forms  of  sensibility  cleared  together^  and  at  the 
end  of  three  weeks  sensibility  was  normal  even  to  the 
compass  test." 

Motor  recovery  after  incomplete  division  follows 
the  same  march  as  after  complete — that  is^  the 
muscles  nearest  the  seat  of  the  injury  first  regain 
voluntary  power  and  excitability  to  the  interrupted 
current. 

In  the  cases  in  which  the  reactions  typical  of  in- 
complete division  are  present^  voluntary  power 
usually  returns  before  the  re-establishment  of 
excitability  to  the  interrupted   current. 

Occasionally    voluntary    power    is    present    from 


INCOMPLETE   DIVISION:    RECOVERY    129 

the  first,  altliougli  excitability  to  the  interrupted 
current  is  lost.  But  this  is  unusual,  as  pointed  out 
in  Chapter  III ;  the  least  severe  form  of  injury  pro- 
duces paralysis  of  the  muscles  supplied  by  the 
aifected  nerve,  with  retention  of  irritability  to  the 
interrupted  current. 

In  all  the  cases  in  which  my  notes  on  the  subject 
are  complete,  voluntary  power  returned  before 
electrical  excitability,  often  some  weeks  before.  In 
cases  uncomplicated  by  sepsis  or  extensive  wounds 
of  the  surrounding  parts,  the  first  return  of  volun- 
tary power  in  the  upper  limb  occurred  in  from 
about  four  to  ten  weeks,  and  progressed  to  complete 
recovery  in  all  the  patients.  In  one  instance  in 
which  the  external  popliteal  nerve  was  affected, 
voluntary  power  did  not  return  for  nine  months,  and 
excitability  to  the  interrupted  current  was  not  present 
two  months  later.  In  another  patient  in  whom  the 
muscles  supplied  by  the  external  popliteal  nerve, 
though  paralysed,  reacted  to  the  interrupted  current, 
voluntary 'power  began  to  return  in  three  and  a  half 
months  and  was  perfect  in  five.  In  another  patient 
in  whom  the  reaction  of  degeneration  developed 
later  no  recovery  took  place  in  two  and  a  half 
years. 

Sensory  recovery  usually  begins  in  about  three 
weeks  and  is  completely  restored  in  about  six 
months. 

But  these  times  of  motor  and  sensory  recovery  are 

9 


130  INJURIES    OF   NERVES 

approximate  only,  and  vary  Avitli  the  severity 
of  the  injury  and  the  distance  of  the  seat  of  # 
the  injury  from  the  periphery.  Cases  in  which 
epicritic  sensibility  alone  is  lost  recover  much  more 
rapidly  than  those  in  which  both  forms  of  sensibility 
are  affected.  When  the  injury,  as  is  so  often  the 
case,  affects  the  brachial  plexus,  considerably  longer 
time  is  necessary  for  the  commencement  and  pro- 
gress of  recovery.  In  one  patient  in  whom  the 
inner  cord  was  injured  as  the  result  of  a  dislocation 
of  the  humerus,  sensory  recovery  did  not  commence 
for  six  months,  and  was  not  perfect  until  fifteen 
months  had  elapsed  since  the  injury. 

To  sum  up,  after  incomplete  division  of  a  mixed 
nerve,  both  forms  of  sensibility  (epicritic  and  proto- 
pathic),  if  lost,  return  at  the  same  time,  commencing 
at  a  date  which  varies  with  the  distance  of  the  injury 
from  the  periphery  from  about  three  weeks  at  the 
wrist  to  six  months  in  the  plexus,  and  also  with 
the  degree  of  the  injury.  Complete  recovery 
as  a  rule  rapidly  ensues.  Muscular  recovery  com- 
mences at  a  time  which  varies  in  the  same  way.  In 
cases  in  which  the  muscles,  though  paralysed,  retain 
their  irritability  to  the  interrupted  current,  recovery 
commences  in  three  or  four  weeks,  sometimes  earlier, 
and  soon  becomes  perfect.  This  degree  of  injury  is 
seen  most  often  as  the  result  of  compression  of  the 
musculo-spiral  nerve,  producing  sleep,  anaesthetic  or 
crutch  paralysis.      If  the  reactions  typical  of  incom- 


INCOMPLETE  DIVISION:    PROGNOSIS    131 

plete  division  are  present  a  much  longer  time  is 
necessary. 

After  neurolysis,  or  when  the  nerve  has  been 
relieved  from  any  form  of  pressure,  recovery  follows 
exactly  the  same  lines. 

Prognosis. — This  is_,  on  the  whole,  good.  Motor 
power  and  irritability  to  the  interrupted  current  are 
restored  and  perfect  sensibility  regained  within  a 
year  in  most  cases.  But  it  must  not  be  forgotten 
that  occasionally,  particularly  in  incomplete  ana- 
tomical division,  in  which  no  treatment  was  adopted 
at  the  time  of  the  accident,  tenderness  may  develop  in 
the  distribution  of  the  affected  nerve  necessitating  a 
complete  resection  of  the  damaged  portion  with  end- 
to-end  suture  ;  in  other  cases  gradual  deterioration 
of  function  occurs. 


CHAPTEE   X 

Pain  complicating  Nerve  Injuries — The  Involvement  of  Nerves  in 
Scar  Tissue — Symptoms  due  to  Involvement  of  the  Trunk  of  a 
Nerve,  Paralytic,  Irritative — Symptoms  due  to  the  Involve- 
ment of  Terminal  Branches — Pain  following  Nerve  Injuries 
the  result  of  Operations  ujDon  the  Kidney,  upon  Herniae — 
Amputation  Neuromata. 

Pain  sometimes  arises  as  the  immediate  result  of 
nerve  injuries^  but  more  often  during  the  after-pro- 
gress of  the  case.  At  the  moment  of  the  infliction 
of  the  injury  pain  may  be  felt  in  the  full  distribution 
of  the  nervCj  but  it  is  never  of  long  duration.  When 
arising  within  a  few  days  of  the  injury  it  is  usually 
the  result  of  infection.  Arising  later,  it  is  usually 
due  to  involvement  of  the  nerve  in  scar  tissue,  either 
in  the  nerve  itself,  the  so-called  interstitial  neuritis, 
or  in  the  tissues  around. 

The  trunk  of  the  nerve  or  one  of  its  terminal 
branches  may  be  affected ;  the  symptoms  produced 
in  both  may  bear  a  superficial  resemblance  to  each 
other.  In  both,  j)ain  may  be  present,  referred  over 
a  large  area,  accompanied  in  some  instances  by  hyper- 
algesia, rarely  by  glossy  skin ;  muscular  wasting  and 
paralysis  may  also  be  present.      But  in  the  first  case 


PAIN    IN    NERVE    INJURIES  133 

(involvement  of  the  trunk)  tlie  pain  and  tenderness 
whicli  often  accompanies  it  marks  out  the  full 
distribution  of  the  affected  nerve,  and  may  be 
accompanied  by  loss  of  sensibility  and  paralysis  of 
muscles,  with  changes  in  their  electrical  excitability ; 
in  the  latter,  the  pain  and  tenderness  map  out  the 
area  of  distribution  of  the  root  or  roots  from  which 
the  injured  twig  arises,  which,  in  only  a  few  cases, 
will  at  all  correspond  to  the  area  of  distribution  of  a 
peripheral  nerve  ;  the  paralysis  is  never  accompanied 
by  electrical  changes  in  the  muscles. 

The  symptoms  vary  in  severity ;  in  some,  slight 
pain  on  movement  or  change  in  the  weather  only  is 
complained  of,  in  others,  pain  of  an  excruciating 
nature  accompanied  by  changes  in  the  skin. 

Symptoms  due  to  involvement  of  the  trunk  of  a 
nerve. — The  cases  in  which  the  trunk  of  a  nerve  is 
involved  may  be  divided  clinically  into  two  groups, 
the  non-irritative  and  the  irritative. 

Non-irritative  groiq^. — In  this  group  the  functions 
of  the  nerve  are  gradually  interfered  with  by  pres- 
sure, and  the  symptoms  are  due  simply  to  interference 
with  conduction ;  pain  and  tenderness  are  absent,  or 
if  pain  is  present  it  is  slight.  The  typical  example 
of  this  form  of  involvement  is  seen  in  the  musculo- 
spiral  nerve,  following  a  fracture  of  the  humerus. 
The   main   points   are   illustrated   by   the   following- 


case 


A  man,  aged  twenty-eight  years,  sustained  a  frac- 


134  INJURIES    OF    NERYES 

ture  of  tlie  lower  third  of  the  humerus.  I  saw  him  two 
weeks  after  the  accident.  All  the  muscles  supplied 
by  the  musculo-spiral  nerve  were  wasted^  paralysed^ 
and  gave  the  reactions  typical  of  incomplete  division. 
At  operation^  twenty-eight  days  after  the  injury,  I 
found  the  nerve  closely  bound  down  by  fibrous  tissue 
to  the  callus.  I  freed  it,  and  sutured  muscle  be- 
neath, in  order  to  prevent  it  from  again  becoming 
adherent  to  bone,  and  wrapped  it  to  prevent  it  from 
forming  adhesions  to  surrounding  parts.  Recovery 
began  in  twelve  weeks,  and  all  the  muscles  supplied 
by  the  injured  nerve  acted  voluntarily  eight  weeks 
later,  and  reacted  again  to  the  interrupted  current 
six  months  after  the  operation." 

The  treatment  of  the  cases  in  this  group  is  simple. 
Neurolysis  is  followed  in  a  short  time  by  recovery, 
providing  care  be  taken  to  avoid  the  occurrence  of 
compression  or  reinvolvement  in  the  scar.  The 
nerve  must  be  protected  from  again  becoming 
adherent ;  it  has  often  happened  that  neglect  of 
this  precaution  has  necessitated  another  operation. 

Irritative  group. — At  the  end  of  the  first  stage  of 
recovery  after  complete  division  the  part  supplied  by 
the  affected  nerve  is  sensitive  everywhere  to  prick, 
but  so  great  is  the  discomfort  produced  by  this 
stimulus  that  it  is  not  infrequently  said  to  be  "  hyper- 
algesic.^'  A  similar  condition  is  seen  in  cases  of 
incomplete  division  with  epicritic  loss.  This  tender- 
ness is  confined  to  the  area  of  loss  of  light  touch  and 


HYPERALGESIA  135 

is  the  expression  of  protopatliic  sensibility.  But 
the  tenderness  associated  with  irritative  involvement 
occupies  the  full  area  of  protopatliic  supply  of  the 
nerve  and  may  be  accompanied  by  no  loss  of  sensi- 
bility. 

The  following  case  illustrates  these  points  : 
"  L.  E — ,  aged  fourteen  years_,  cut  his  forearm  with 
broken  glass.  The  wound  was  sutured  and  healed 
by  first  intention.  Two  weeks  later  he  began  to 
suffer  pain,  and  the  wound  was  reopened  without 
effect ;  the  pain  gradually  increased  in  severity.  I 
saw  him  fourteen  weeks  after  the  accident ;  a  scar 
was  present  on  the  anterior  surface  of  the  forearm, 
two  and  three  quarter  inches  above  the  fold  of  the 
wrist.  Extending  downwards  from  this  the  full 
distribution  of  the  anterior  branch  of  the  external 
cutaneous  nerve  was  mapped  out  by  extreme 
tenderness.  There  was  no  loss  of  any  form  of 
sensibility. 

"  The  nerve  branch  was  exposed  at  the  seat  of  the 
injury  and  found  implicated  in  fibrous  tissue  and 
adherent  to  the  scar  ;  it  had  evidently  suffered  incom- 
plete anatomical  division.  The  damaged  portion  was 
excised  and  the  ends  of  the  nerve  brought  together. 
No  loss  of  sensibility  followed  the  operation,  the 
anterior  branch  of  the  external  cutaneous  nerve  of 
the  forearm  having  no  exclusive  sensory  supply. 
The  patient  lost  his  pain  at  once  and  has  since 
remained  free." 


136  IIS'JURIES    OF    NERVES 

Tlie  condition  may  also  follow  a  subcutaneous 
injury.  ^'  A  boy  fell  astride  a  gate  and  bruised  liis 
perineal  region.  He  was  kept  in  bed  for  several 
Aveeks^  the  diagnosis  of  fractured  pelvis  having  been 
made.  ^  Several '  days  after  the  accident  pain  and 
tenderness  appeared^  the  pain  radiating  from  the 
point  injured  to  the  scrotum. 

"When  I  saw  him  nine  weeks  after  the  accident 
he  was  unable  to  Avalk  without  great  pain  ;  when 
walking  he  kept  the  hip-joint  of  the  affected  side 
rigidj  for  he  had  found  by  experience  that  all  move- 
ment of  the  hip  increased  the  pain.  Marked  hyperal- 
gesia was  present  running  from  a  tender  spot  over  the 
ramus  of  the  ischium  to  the  rio-ht  side  of  the  scrotum. 
After  division  of  the  nerve  all  pain  ceased  and  the 
tenderness  disappeared." 

I  have  had  to  operate  also  in  two  cases  in  which 
the  posterior  division  of  the  external  cutaneous 
nerve  of  the  forearm  was  injured  as  the  result  of 
a  direct  blow  over  the  external  condyle  of  th& 
humerus. 

The  patients  usually  present  themselves  with 
symptoms  resembling  those  I  have  just  described. 
But  occasionally^  most  often  as  the  result  of  a  gun- 
shot wound,  the  symptoms  are  of  much  greater 
severity.  Instances  have  been  recorded  after  all 
the  more  recent  wars.  In  1813  Denmark  reported 
the  case  of  a  man  wounded  at  the  storming  of 
Badajoz.      The  bullet  entered  one  and  a  half  inches 


CAUSALGIA  137 

above  tlie  inner  condyle  of  the  liumerus  and  came 
out  on  the  outer  side^,  in  front  of  the  elbow-joint. 
He  describes  the  condition  as  follows  :  ^'  I  always 
found  him  with  the  forearm  bent  and  in  the  supine 
position,  and  supported  by  the  firm  grasp  of  the 
other  hand/^  The  pain  ''  was  of  a  burning  nature 
and  so  violent  as  to  cause  a  continual  perspiration 
from  his  face.  He  had  an  excoriation  on  the  palm 
from  which  exuded  an  ichorous  discharge. ^^ 

This  is  an  excellent  description  of  the  pain  and 
of  the  '^  trophic ''  sore,  which  probably  originated  as 
a  blister,  but  no  account  is  given  of  the  other  skin 
changes  which  may  accompany  it.  These  were  first 
described  by  Hamilton  in  1838.  He  stated  that 
"the  pain  may  be  accompanied  by  redness  and 
swelling  resembling  the  appearance  of  the  skin  in 
inflammation  of  the  fascia  or  a  deep  collection  of 
matter.''^ 

A  fuller  description  was  given  by  Paget  in  1864 
{vide  p.  41),  but  to  Mitchell,  Morehouse,  and  Keen 
is  due  the  credit  of  the  exact  picture  of  this  con- 
dition [vide  Chapter  111). 

I  had  the  opportunity  of  examining  several  such 
cases,  due  to  bullet-wounds  received  during  the  late 
war  in  South  Africa.  The  following  record  illus- 
trates admirably  the  most  important  points  of  these 
severe  cases. 

"  L.  G.  H —  was  wounded  at  Tweefontein  on  July 
22nd,  1901,  by  a  bullet  that  entered  four  and  a  half 


138  INJURIES    OF    NERVES 

inclies  below  the  internal  condyle  of  tlie  linmeriis  and 
passed  across  the  forearm  to  the  radial  side.  The 
arm  did  not  become  painful  until  he  had  been  in 
hospital  three  weeks ;  the  pain  then  gradually 
increased  in  severity^  and  when  I  saw  him  with 
Dr.  Head  on  January  26th;  1902,  was  constant. 

^^  The  skin  of  the  affected  hand  was  smooth,  glossy, 
and  of  a  pinkish  blue  colour,  covered  with  beads  of 
sweat,  the  fingers  tapered  and  the  nails  were  thin, 
long  and  curved.  The  hand  was  intensely  tender 
over  a  large  area  occupying  the  palm,  the  ulnar  half 
of  the  thenar  eminence,  the  palmar  aspect  of  the 
little,  ring  and  middle  fingers.  Over  the  dorsal 
surface  this  tenderness  occupied  the  ulnar  half  of 
the  hand  and  extended  to  the  tendon  of  the  ring 
finger,  and  the  dorsal  surface  of  the  little,  ring  and 
middle  fingers.  The  tender  skin  was  intensel}? 
sensitive  to  pinching,  to  pressure  with  the  head  of  a 
pin  and  to  the  pm-point.  Epicritic  sensibility  was 
lost  over  the  usual  ulnar  area.  Sensibility  to  the 
extreme  degrees  of  temperature  was  present  every- 
where. Operation  revealed  incomplete  anatomical 
division  of  the  ulnar  nerve  in  the  forearm,  the  ends 
being  intimately  bound  up  in  a  mass  of  fibrous 
tissue.  Complete  division  of  the  nerve,  removal  of 
the  damaged  portion  and  re-establishment  of  con- 
tinuity completely  relieved  the  pain.  Sensibility 
returned  to  the  hand  by  the  usual  stages.^' 

The    latent    period    which    existed    in   this    case 


CAUSALGIA  139 

between  the  injury  and  the  onset  of  pain  is  typical, 
nothing  abnormal  being  noticed  at  first;  in  many 
cases  the  wound  heals  by  primary  union  or  aseptic 
granulations. 

The  pain  is  intense  and  described  by  the  patient 
as  "  burning  '^  or  ^'  bursting  '^  in  character.  It  is 
aggravated  by  all  external  stimuli  and  is  felt  over  the 
full  protopathic  distribution  of  the  nerve — a  larger 
area  than  becomes  insensitive  to  prick  on  section  of 
the  nerve.  It  is  accompanied  by  tenderness,  usually 
by  sweating,  sometimes  by  glossy  skin  and  blisters. 

The  degree  of  interference  with  the  functions  of 
the  nerve  varies  with  the  amount  of  injury  the  nerve 
has  sustained,  but  is  always  incomplete.  In  the 
patient  just  described  the  muscles  were  paralysed, 
but  in  a  patient  with  a  similar  condition  of  the  ulnar 
nerve  the  muscles  acted  well.  Causalgia  never 
arises  with  complete  interruption  of  continuity.  It 
results  from  the  irritation  of  the  protopathic  fibres  of 
the  affected  nerve,  and  is  a  further  proof  of  the 
existence  of  the  efferent  impulses  in  afferent  nerves 
called  by  Bayliss  "  antidromic." 

Treatment  consists  in  resection  of  the  damaged 
portion  of  the  nerve  and  restoration  of  anatomical 
continuity  by  suture  or  transplantation. 

Symptoms  following  the  involvement  of  terminal 
branches. — It  was  well  known  to  the  surgeons  at  the 
end  of  the  eighteenth  and  the  beginning  of  the  nine- 
teenth   centuries    that    a     very      definite     train     of 


140  INJURIES    OF    NERVES 

symptoms  might  follow  the  wounds  of  small  nerves. 
These    cases    seem  to  have  been  first  described  by 
Abernethy.     Wardrop,  in  1823,  recorded  a  case  in 
which  pain  in  the   whole  distribution   of  the  radial 
nerve  followed  ten  days  after  a  wound  on  the  radial 
border   of  the   thumb.      Neurotomy   of  the  affected 
branch  gave  immediate  relief.      Hamilton^  in   1838, 
wrote    a    paper    on    the    subject,    gi^iiig    instances 
following   injuries   to   nerve   branches  from   various 
causes,  in  some  cases  due  to  the  operation  of  phle- 
botomy.     They  were  accompanied  by  tenderness  of 
the  skin,  and  in  some   cases   by  paralysis  or  spasm 
and  contracture  of  the  muscles  of  the  limb,  and  were 
often  accompanied  by  symptoms  now  called  hysterical. 
In   some   of  the   instances  mentioned    neuritis  may 
have  been  the  cause,  particularly  in  those  that  came 
on  in  which  the   symptoms  supervened  a  short  in- 
terval   after   the  injury,  but  most  were  not  of  this 
nature,    although   commonly    called   neuritis.      Yery 
little    attention   seems   to   have    been    paid  to  these 
cases  of  late  years.      The  most  modern  paper  of  im- 
portance on  the  subject  was  written  by  the  late   Sir 
W.  Mitchell  Banks,  in  1869. 

Irritation  of  one  of  the  terminal  branches  of  the 
fifth  nerve  may  cause  pain  and  tenderness,  referred 
to  the  whole  of  the  distribution  of  that  branch  to 
which  it  belongs ;  this  is  now  a  commonplace  of 
medicine.  But  similar  symptoms  may  follow  the  in- 
volvement of  the  branch  of  any  nerve  in  scar  tissue, 


INVOLVEMENT  OF  TERMINAL  BRANCHES  141 

the    result   of   a   wound^   or    in   some   cases^   a   sub- 
cutaneous injury. 

As  occurs  wlien  the  trunk  of  a  nerve  is  involved, 
an  interval  always  elapses  between  the  injury  and 
the  first  symptom.  The  pain  is  usually  widespread, 
extending  over  the  full  protopathic  distribution  of 
the  root  or  roots  involved,  and  is  often  accompanied 
by  hyperalgesia.  There  may  be  in  addition,  par- 
ticularly in  the  lower  limb,  paresis  or  paralysis  of  the 
muscles  supplied  by  the  corresponding  nerve  or  root. 

The  following  case  brings  out  the  imiDortant 
points:  ^'^Gr.  L — ,  aged  thirty-six  years,  crushed  his 
right  foot  in  September,  1902,  fracturing  the  first  and 
second  metatarsal  bone.  At  first  the  pain  was 
entirely  local,  but  in  a  few  weeks  it  involved  the 
whole  of  the  great  sciatic  area  and  increased  in 
severity.  All  the  muscles  of  the  leg  supplied  hj 
this  nerve  were  weak  and  wasted.  He  Avas  admitted 
to  the  London  Hospital  in  May,  1903,  and  treated 
by  rest  and  massage,  various  forms  of  electricity, 
injections  of  strychnine,  all  without  success.  In 
September,  1903,  one  year  after  the  injury,  I 
explored  the  first  metatarsal  space  and  found  the 
branch  of  the  anterior  tibial  nerve,  which  runs  to  the 
cleft  between  the  great  and  second  toes,  involved  in 
fibrous  tissue.  It  was  impossible  to  free  it  entirely, 
so  I  removed  the  involved  portion  and  performed 
end-to-end  suture.  He  lost  his  pain  at  once,  but  it 
was  over  a  year  before  full  power  was  restored  to 


142  INJURIES    OF    NERYES 

the  wasted  muscles.  At  the  end  of  this  time  he  was 
quite  well  and  has  remained  so  since. '^ 

These  cases  are  often  described  as  chronic  trau- 
matic neuritis.  But  the  symptoms  arise  in  in- 
dividuals who  are  otherwise  healthy,  in  injuries  that 
are  often  subcutaneous,  or  if  open,  heal  by  first 
intention,  and  the  jDain  and  tenderness  disappear 
immediately  after  removal  of  the  damaged  portion  of 
the  nerve.  It  is  obvious,  therefore,  that  the  term 
''  chronic  neuritis  "  does  not  adequately  express  the 
condition. 

Treatment  should  be  operative ;  much  valuable 
time  is  wasted  by  general  treatment.  If  the  con- 
dition be  recent,  and  the  patient  object  to  operation, 
absolute  rest  should  be  tried  ;  massage  and  electrical 
treatment  are  absolutely  useless  unless  the  cause  be 
first  removed  by  operation. 

The  damaged  portion  of  the  nerve  must  be  re- 
moved, and  communication  with  the  central  nervous 
system  restored,  if  possible,  by  end-to-end  suture  or 
anastomosis.  But  the  size  of  the  nerve  involved  may 
render  this  impracticable — for  example,  when  one  of 
the  terminal  branches  of  a  digital  nerve  is  involved 
in  scar  tissue.  The  best  treatment  in  these  cases 
consists  in  excision  of  the  scar,  and  suture  or  Wolfe's 
grafting;  in  some  cases  amputation  of  the  affected 
portion  may  be  necessary. 

Although  in  the  recent  cases  pain  and  tenderness 
disappear    immediately,    cure   is   not,   as   a   rule,    so 


CHRONIC    NEURITIS  143 

rapid  in  the  case  of  a  mixed  nerve.  The  condition 
of  the  patient  may  make  him  more  susceptible  to  the 
small  area  of  anaesthesia  which  may  have  resulted 
from  the  operation,  and  recovery  may  be  delayed 
until  regeneration  has  taken  place.  If  the  muscles 
are  wasted  and  paretic^  months  may  elapse  before 
they  regain  their  full  power.  During  the  interval 
the  limb  should  be  kept  at  rest  in  such  a  position 
that  the  aifected  muscles  are  flaccid.  The  splint 
should  be  removed  daily  for  massage,  and,  if  jDOSsible, 
stimulation  Avith  the  interrupted  current,  to  which 
the  muscles  always  react.  The  patient  should  be 
encouraged  to  use  the  affected  muscles,  and  as  soon  as 
voluntary  power  is  re-established,  the  splint  removed. 

These  cases  are  not  infrequently  met  with  in 
connexion  with  claims  for  comjDensation ;  an  injury 
of  this  nature  will  certainly,  if  muscles  are  affected, 
incapacitate  the  patient  for  a  year,  even  if  operated 
upon  early. 

The  diagnosis  of  hysteria  is  often  made ;  un- 
doubtedly in  many  cases  hysterical  symptoms  super- 
vene, but  careful  examination  will  always  reveal  the 
nerve  affected  and  lead  to  the  correct  treatment. 

Occasionally  a  true  chronic  neuritis  is  set  up ;  in 
these  cases  removal  of  the  damaged  portion  of  the 
nerve  fails  to  secure  relief,  or  the  relief  is  transient ; 
nothing  remains  but  excision  of  the  root  ganglia 
corresponding  to  the  roots  affected,  or  intra-dural 
division  of  roots. 


144  INJURIES    OF    NERVES 

Pain  following  nerve  injuries,  the  result  of  operations. — 
As  I  have  already  pointed  out  in  Chapter  I^  injuries 
of  the  smaller  nerves  during  the  course  of  a  well- 
planned  operation  are  soon  recovered  from.  But  it 
occasionally  happens  that  irritative  symptoms  arise 
from  the  involvement  of  a  trunk  or  terminal  branch 
iu  fibrous  tissue.  The  last  dorsal^  ilio-hypogastric 
or  ilio-inguinal  nerves  may  be  injured  during  the 
course  of  operations  upon  the  kidney^  unless  care  be 
taken  to  make  all  incisions  parallel  to  their  course. 
In  most  of  these  cases  no  pain  is  complained  of  while 
the  patient  is  in  bed^  and  symptoms  appear  when  the 
patient  first  gets  up^  and  increase  in  severity.  Pain 
and  tenderness  are  complained  of  below  the  scar ;  this 
may  be  severe  enough  to  make  the  pressure  of  clothes 
around  the  waist  unendurable. 

Examination  usually  reveals  no  loss  of  sensibility, 
but  a  well-marked  area  of  tenderness  corresponding 
to  the  nerve  involved.  This  can  be  marked  out  in 
the  usual  way  by  dragging  the  point  of  a  pin  lightly 
across  the  skin^  from  sound  to  aifected  parts.  It 
occasionally  happens  that  one  of  these  nerves  is 
completely  divided ;  this  may  produce  a  loss  of 
epicritic  sensibility,  with  resultant  exposure  of  pro- 
topathic  sensibility.  All  stimuli  over  the  area  have 
then,  the  unpleasant,  painful,  radiating  character 
associated  with  this  form  of  sensibility. 

In  both  cases  the  injured  nerve  must  be  exposed 
by    operation.      If    it    has    been    cut   into   and   the 


PAIN    FOLLOAVINa    OPERATIONS       145 

syiiiptoiiis  arc  irritativ^e  the  damaged  portion  must 
be  resected  and  end-to-end  siittire  performed^  or,  if 
it  is  involved  in  scar  tissue  only,  freed,  and  pre- 
cautions taken  to  ^irevent  its  recurrence.  If  it  be 
found  divided  an  attempt  must  be  made  to  bring 
the  ends  into  apposition  ;  if  tliis  fails,  anastomosis  to 
one  of  the  parallel  nerves  must  be  carried  out. 

The  ilio-ino'Liinal  nerve  is  liable  to  iuiurv  in  the 
performance  of  radical  cure  of  inguinal  hernia.  It 
should  always  be  seen  and  avoided  as  it  passes  out 
at  the  external  abdominal  I'ing  below  and  to  the 
outer  side  of  the  cord.  Injury  will  produce  pain 
and  tenderness  in  its  distribution,  aggravated  by 
exertion,  and  may  be  severe  enough  to  prevent  the 
patient  from  following  his  employment.  In  some 
cases  it  is  accompanied  by  pain,  referred  to  the 
whole  first  lumbar  distribution. 

Treatment  is  on  the  lines  alreadv  laid  down. 

tJ 

Irritation  of  terminal  branches  as  the  result  of 
involvement  in  scar  tissue  may  occasionally  give  rise 
to  difficulties  in  diagnosis.  It  arises  in  its  most 
typical  form  after  amputation  of  the  breast.  In  this 
operation  the  perforating  branches  of  the  intercostal 
nerves  are  divided,  and  their  involvement  may  give 
rise  to  severe  symptoms.  If  the  first  or  second 
dorsal  be  involved,  pain  is  felt  radiating  down  the 
inner  side  of  the  arm  and  forearm,  often  accompanied 
by  tenderness. 

The  following  is  an  example  : 

10 


146  INJURIES    OF    NERVES 

"  In  November,  1905,  I  carried  out  the  complete 
operation  for  mammary  carcinoma.  The  flaps  did 
not  come  well  into  contact,  and  a  small  area  was  left  at 
their  upper  part  which  healed  by  granulation.  The 
patient  was  entirely  free  from  symptoms  until  early 
in  1906  pain  commenced  and  increased  in  severity, 
bringing  her  to  see  me  in  November  of  that  year. 
She  stated  that  the  pain  started  in  the  upper  part  of 
the  scar  and  radiated  down  the  inner  side  of  the  arm 
and  forearm,  and  was  worse  on  moving  the  arm.  Over 
the  inner  end  of  the  second  intercostal  space  was  a 
tender  spot,  palpation  of  which  caused  the  pain  to 
shoot  down  the  inner  side  of  the  arm.  The  skin  of 
the  inner  side  of  the  arm  in  the  region  supplied  by 
the  intercosto  -  humeral  nerve  was  tender  to  the 
slightest  touch. 

"  I  excised  the  tender  portion  of  the  scar,  and  after 
freeing  the  skin  sutured  the  flaps  over  Cargile  mem- 
brane. She  lost  her  pain  and  tenderness  at  once 
and  has  since  remained  free." 

The  rules  for  the  treatment  of  nerves  involved  in 
scar  tissue  may  be  summed  up  as  follows  : 

When  the  symptoms  produced  are  those  of  incom- 
plete divisioi),  neurolysis  and  protection  of  the 
recently  freed  portion  should  be  adopted.  When 
irritative  symptoms  are  present  and  the  trunk  of  the 
nerve  involved,  excision  of  the  damaged  portion, 
followed    by    restoration    of    continuity.       When    a 


AMPUTATION    NEUROMATA  147 

terminal  branch  is  affected,  excision  of  the  dama^-ed 
portion  of  nerve. 

Amputation  neuromata. — When  a  nerve  is  completely 
divided  the  lihres  of  the  upper  end  spread  out  in  a 
brush-like  manner.  This  "  mop-like  protuberance 
formed  immediately  a  nerve  trunk  is  divided/^  was 
described  by  Ballance  and  Purves  Stewart  as  "  the 
primitive  end  bulb.^^  New  axis  cylinders  are  deve- 
loped in  this,  and  the  bulb  eventually  becomes  a 
mass  of  fibrous  tissue  Avith  small  nerve-fibres  inter- 
lacing in  all  directions. 

After  all  amputations  such  bulbs  must  be  formed 
on  the  central  ends  of  the  severed  nerves,  but  only 
in  a  few  instances  do  their  presence  give  rise  to 
symptoms. 

When  the  ends  of  the  nerve  are  pulled  down,  cut 
short  and  crushed  with  a  pair  of  S^^encer  Wells' 
forceps  at  the  time  of  the  operation,  symptoms  rarely 
ensue.  They  arise  from  irritation  of  the  bulb  by 
direct  pressure  or  by  the  traction  of  muscles  or 
adhesions.  The  size  of  the  bulb  varies  widely,  and 
it  may  be,  as  suggested  by  Alexis  Thomson,  that  the 
increased  size  in  some  cases  is  due  to  inflammation, 
and  that  the  condition  has  become  less  frequent  now 
that  the  principles  of  Listerian  surgery  are  carried 
out. 

Pain  or  discomfort  after  an  amputation  correctly 
performed  is  unusual.  For  the  first  few  days  the 
patient  may  be  acutely  conscious  of  the  absent  limb 


148  INJURIES    OF    NERVES 

and  may  describe  its  exact  position  in  space^  but 
unless  inflammation  occurs  pain  is  absent.  The 
consciousness  of  the  position  of  the  absent  member 
may  never  be  lost^  and  any  irritation  of  the  bulb  will 
cause  the  pain  to  be  referred  to  the  area  of  the 
absent  limb  which  was  supplied  by  the  fibres  affected. 
Thus^  in  a  patient  in  whom  symptoms  pointing  to 
irritation  of  the  end  bulb  originated  twenty-three 
years  after  an  amputation  of  the  foot^  the  reference 
of  the  pain  to  the  inner  side  of  the  absent  limb  led 
to  the  discovery  of  the  bulb  on  the  stum])  of  the 
internal  saphenous. 

The  symptoms  resemble  those  described  as  due  to 
irritation  of  the  terminal  branch  of  a  nerve,  modified 
by  the  absence  of  a  part  of  the  limb.  There  may  be 
pain  widespread  in  the  distribution  of  the  nerve  in- 
volved, accompanied  by  tenderness  of  that  portion  of 
the  stump  supplied  by  branches  from  the  roots 
involved,  and  in  some  cases  accompanied  by  changes 
in  the  skin.  The  pain  may  be  produced  by  direct 
pressure  on  the  bulb,  and  is  often  felt  with  changes 
of  the  weather.  Muscular  twitchings  often  occur  in 
association  with  the  pain,  and  hysterical  symptoms 
may  be  present. 

The  time  after  the  amputation  at  which  the 
symptoms  first  appear  is  variable,  but  the  longest 
interval  that  has  come  under  my  notice  Avas  in  the 
case  just  quoted — twenty-three  years. 

The   treatment   should    be    preventive — in    every 


AMPUTATION    NEUROMATA  149 

amputation  the  nerves  slioulcl  be  pulled  down  and 
cut  short  with  scissors  to  prevent  their  involvement 
in  the  fibrous  tissue  at  the  scar,  and  the  ingrowth  of 
fibrous  tissue.  It  has  been  proved  experimentally 
that  crushing  the  end  of  a  nerve  prevents  the  forma- 
tion of  a  large  end  bulb. 

When  symptoms  are  present  the  bulb  and  three  or 
four  inches  of  the  affected  nerve  must  be  removed. 
This  has  sometimes  failed  to  relieve  the  pain;  in  these 
cases  intra-dural  division  of  posterior  roots  should  be 
performed  if  the  symptoms  are  severe. 


CHAPTER  XI 

Method  of  Injury  of  Cranial  Nerves—  Olfactory  Nerves  :  Method 
of  Testing  Smell— Optic  Nerve — Ocnlo-motor  Nerves— Fifth 
Nerve  :  Method  of  Injury  :  Loss  of  Sensibility :  Taste  Fibres  : 
Taste  Tests :  Motor  Supply  of  Palatal  Muscles  :  Corneal 
Changes — Facial  Nerve  :  Varieties  of  Injury :  Anastomosis — 
Auditory  Nerve — Glosso-pharyngeal  Nerve — Vagus  Nerve — 
Spinal  Accessory  Nerve :  Paralysis  of  Trapezius  Muscle  — 
Hypoglossal  Nerve, 

Appections  of  the  cranial  nerveR^  with  the  ex- 
ception of  the  facial  and  spinal  accessory,  are  rare  in 
surgical  practice.  They  are  injured  most  often  as  the 
result  of  operative  procedures  and  fractures  of  the 
base  of  the  skull.  The  facial  is  the  nerve  most  often 
injured  in  the  latter  way.  Eawling  found  some 
interference  with  the  functions  of  this  nerve  in 
twenty-four  out  of  sixty  patients ;  Kohler  in  twenty- 
two  out  of  forty,  although  other  authors  do  not  give 
such  a  large  percentage.  Next  in  order  of  fre- 
quency are  the  auditory,  the  sixth,  optic,  third  and 
fourth. 

Olfactory  nerves. — Injury  to  the  olfactory  nerves 
and  the  bulb  into  which  they  pass  must  be  considered 
together,  as  the  symptoms  produced  by  their  injury 
are  identical. 


LOSS    OF    SMELL  151 

Loss  of  smell  not  infrequently  complicates  a 
fracture  of  the  anterior  fossa  of  the  skull  or  of  the 
nasal  bones_,  resulting  from  direct  violence^  but  in 
only  a  few  of  these  cases  is  it  due  to  nerve  injury. 
Anosmia  may  also  follow  blows  on  the  back  of  the 
head  which  do  not^  so  far  as  can  be  ascertained, 
cause  a  fracture  of  the  anterior  fossa. 

The  patient  usually  complains  of  inability  to  taste, 
less  often  of  the  loss  of  smell.  In  the  majority  of 
cases  an  immediate  diagnosis  of  nerve  injury  is  im- 
possible ;  the  nasal  cavity  is  filled  with  blood-clot, 
and  the  injury  to  the  roof  of  the  nasal  cavity  may 
render  testing  impossible  for  a  time. 

Li  testing  for  loss  of  the  sense  of  smelly  irritating 
and  pungent  substances  which  may  stimulate  the 
sensory  branches  of  the  fifth  nerve  must  be  avoided. 
Aromatic  volatile  materials,  such  as  oil  of  cloves, 
peppermint,  and  assaf  oetida  should  be  employed,  each 
nostril  being  tested  separately. 

Recovery  usually  follows  loss  of  smell,  compli- 
cating fractures  of  the  skull  or  nasal  bones.  Per- 
manent anosmia  is  rare  from  an  injury  to  the 
olfactory  nerves  or  bulb. 

Optic  nerve. — This  nerve  rarely  suffers  direct  in- 
jury. It  may  be  injured  in  penetrating  wounds  of 
the  orbit  or  temporal  region ;  gunshot  wounds  in  the 
temporal  region  have  injured  both  optic  nerves  with- 
out causing  any  injury  to  the  eyeball.  It  is  some- 
times injured  in  fractures  of  the  base   of  the  skull. 


152  INJURIES    OF    NERYES 

involved   in    orbital    cellulitis^,    or    the  fibrous  tissue 
resulting  from  it^  or  pressed  upon  by  growth. 

Unilateral  blindness  has^  in  rare  instances, 
followed  a  severe  head  injury  unaccompanied  by  any 
evidence  of  a  fractured  base.  This  is  usually 
explained  as  due  to  a  haemorrhage  into  the  nerve, 
but  Rawling  has  suggested  that  it  may  result  from  a 
fracture  through  the  base  of  the  anterior  clinoid 
process,  the  fragment  exercising  direct  pressure  on 
the  nerve. 

A  complete  division  of  the  nerve  causes  loss  of 
vision  in  the  affected  eye,  with  more  or  less  dilatation 
of  the  pupil.  Ophthalmoscopic  examination  later 
reveals  optic  atrophy. 

Oculo-motor  nerves. — These  nerves  are  most  often 
injured  in  fractures  of  the  base  of  the  skull,  next  in 
order  of  frequency  during  operations  for  removal  of 
the  Gasserian  ganglion  as  they  lie  in  the  outer  wall 
of  the  cavernous  sinus,  or  by  the  pressure  of  orbital 
tumours.  Most  of  these  cases  come  under  the  care 
of  the  ophthalmic  surgeon. 

The  sixth  nerve  most  often  suffers  in  a  fracture  of 
the  base  by  reason  of  its  anatomical  position,  being 
implicated  as  it  lies  on  the  side  of  and  grooves  the 
dorsum  sellae,  next  the  third,  rarely  the  fourth.  The 
third  nerve  is  more  often  affected  by  causes  other 
than  injury. 

In  examining  for  signs  of  involvement  of  the 
ocular  nerves,  the  position  of  the  eye  should  be  first 


THIRD    CRANIAL    NERA^E  153 

noted,  its  protrusion  or  recession,  and  the  presence 
or  absence  of  squint.  The  patient  should  then  be 
asked  to  follow  the  movements  of  the  observer's 
finger  in  the  necessary  directions,  to  detect  weakness 
or  paralysis  of  any  muscle.  The  size,  shape  and 
reactions  of  the  pupil  to  light  and  accommodation  must 
also  be  noted. 

The  patient,  in  most  cases,  complains  of  diplopia, 
and  this  may  be  the  only  symptom  indicative  of 
injury  to  one  of  the  nerves  supplying  the  ocular 
muscles.  For  the  investigation  of  this  symptom 
the  reader  is  referred  to  works  on  ophthalmic 
surgery. 

The  third  nerve. — Injury  to  this  nerve  is  un- 
common, although  paralysis  of  some  of  the  muscles 
supplied  by  it  is  by  no  means  rare. 

The  nerve  may  suffer  injury  in  fractures  of  the 
base  of  the  skull  often  with  other  nerves,  particu- 
larly the  first  division  of  the  fifth  and  the  optic. 
Injury  to  the  whole  nerA^e  is  unusual ;  in  most  cases 
some  only  of  its  branches  are  affected,  ptosis  and 
dilatation  of  the  pupil  often  occurring  without 
external  strabismus. 

Complete  division  of  the  nerve  produces  ptosis 
from  paralysis  of  the  levator  palpebra?  superioris 
with  over-action  of  the  frontalis,  so  that  the  eyebrow 
is  hio'her  than  on  the  sound  side.  There  is  slio-ht 
exophthalmos  and  the  pupil  is  dilated  and  does  not 
react  to  lio-ht  or  accommodation.    External  strabismus 


154  INJURIES    OF    NERVES 

is  present^  and  the  patient  is  unable  to  move  tlie  eye 
upwards^  downwards,  or  inwards. 

Fourth  nerve. — Tliis  nerve  is  rarely  injured  alone. 
Its  division  causes  paralysis  of  the  superior  oblique 
muscle,  with  impaired  power  of  downward  movement. 
This  deficient  movement  is  difficult  to  detect;,  but  the 
characteristic  diplopia  on  looking  downwards  and  the 
feeling  of  giddiness  on  going  downstairs  is  charac- 
teristic. 

Sixth  nerve. — This  nerve  most  often  suffers  in 
fractures  of  the  base  of  the  skull.  Its  injury  pro- 
duces internal  strabismus,  with  inability  to  turn  the 
eye  outwards. 

Fifth  nerve. — Injuries  of  this  nerve  or  of  its 
branches  are  uncommon ;  it  acquires  its  surgical 
importance  chiefly  in  connexion  with  trigeminal 
neuralgia.  It  may  be  injured  in  fractures  of  the 
base  of  the  skull  or  jaws,  or  from  involvement  in 
the  products  of  bone  disease,  or  pressed  upon  by 
inflammatory  collections  or  growth  in  the  frontal 
sinus,  maxillary  antrum  or  skull.  Involvement  of 
the  whole  nerve  is  unusual,  one  of  its  branches  only 
being  affected  in  most  cases. 

Makins  has  recorded  the  following  facts  with 
regard  to  gunshot  wounds  involving  this  nerve.  It 
suffered  most  often  in  fractures  of  the  jaws ;  a  whole 
division  was  rarely  affected,  and  the  loss  of  sensi- 
bility was,  as  a  rule,  temporary. 

Sensory  symptoms. — It  must  be  remembered  that 


FIFTH  NERVE  :    SENSORY  SYMPTOMS  155 

the  fiftli  nerve,  when  injured_,  behaves  just  as  any 
other  peripheral  nerve ;  that  j^ressure  upon  the  nerve 
or  involvement  in  growth  will  produce  a  loss  of 
sensibility  exactly  similar  to  that  produced  by  pres- 
sure upon  the  median  or  ulnar  nerves.  This  is 
especially  important  to  remember  in  connexion  with 
pain  in  the  distribution  of  this  nerve  and  its  treat- 
ment by  operation.  Interference  with  the  functions 
of  the  nerve  or  one  of  its  branches  produces  a  loss 
of  sensibilit}--^  first  to  light  touchy  then  to  pain.  If 
severe  pain  is  being  caused  as  the  result  of  pressure 
ujDon  the  nerve,  some  alteration  in  sensibility  will  be 
found  ;  on  the  other  hand,  in  some  of  the  cases  of 
referred  pain  and  in  trigeminal  neuralgia  major  no 
sensory  loss  is  j)i'esent. 

The  exclusive  supply  of  the  fifth  nerve  is  most 
readily  studied  in  patients  who  have  undergone  the 
operation  of  removal  of  the  Gasserian  ganglion.  Its 
full  supply  is  shown  in  cases  of  division  of  the 
sensory  branches  of  the  cervical  plexus  {vide  Plate  YI, 
p.  178),  but  as  there  is  very  little  overlap  between 
it  and  the  cervical  nerves,  its  exclusive  and  full 
supply  are  almost  identical. 

The  exclusive  supply  was  first  sj^stematically 
studied  by  Krause,  and  is  described  in  his  well-known 
monograph.  But  it  is  largely  owing  to  the  re- 
searches of  Harvey  Gushing,  confirmed  recently  in 
many  respects  by  Morriston  Davies,  that  our  know^- 
ledge  is  due. 


156  INJUEIES    OF    NERVES 

The  loss  of  sensibility  resulting  from  removal  of 
the  Grasserian  ganglion  is  smaller  than  would  have 
been  supposed  from  reading  a  description  of  its 
supply^  as  ascertained  by  dissection.  While  varying 
somewhat  from  individual  to  individual^  it  retains  in 
all  its  peculiar  outline. 


Fig.  10. — To  show  the  loss  of  sensibility  resnlting-  from  removal 
of  the  Gasserian  gangiion. 

Sensibility  to  light  touch  and  to  prick  are  lost 
over  an  area  which  is  almost  identical^  but  fails  to 
correspond  in  the  region  of  the  external  ear  and  the 
nose.  Morriston  Davies  gives  an  accurate  descrip- 
tion of  the  area  of  epicritic  loss,  from  which  the 
following  description  is  taken.  Its  anterior  boundary 
is  the  mid-lino  of  the  forehead  and  chin.     Its  posterior 


FIFTH  NERA^E  :   SENSORY  SYMPTOMS  157 

border  may  be  described  as  consisting  of  three 
straight  lines  {vide  Fig.  10).  The  upper  is  almost 
vertical  and  extends  from  a  point  in  the  sagittal 
plane^  midway  between  the  nasion  and  the  inion,  to 
the  free  margin  of  the  tragus  at  the  junction  of  its 
middle  and  lower  thirds ;  thence  the  second  line 
passes  horizontally  forwards  to  a  point  midway 
between  the  external  auditory  meatus  and  the  outer 
canthus  of  the  eye  ;  here  the  third  line  begins  and 
runs  obliquely  down  to  a  point  on  the  lower  border 
of  the  chin  vertically  below  the  angle  of  the  mouth. 

The  posterior  boundary  of  the  loss  of  sensibility  to 
prick  runs  a  much  straighter  course  anterior  to  the 
line  described  above.  The  anterior  wall  of  the 
external  auditory  meatus  and  the  anterior  portion  of 
the  tympanic  membrane  are  usually  insensitive  to 
light  touch  and  to  prick. 

It  seems  probable  that  deep  touch  is  lost  over  an 
area  corresponding  roughly  to  that  of  the  loss  of 
sensibility  to  prick,  and  with  it  loss  of  sense  of 
position  and  movement  in  the  muscles  of  the  face. 
Gushing  found  loss  of  the  sense  of  active  movement 
in  the  facial  muscles  when  stimulated  with  the  inter- 
rupted current,  and  also  loss  of  the  sense  of  passive 
position.  Joy  and  Johnson  and  Spiller  have  recorded 
cases  in  which  "  deep  sensibility "  was  present. 
Morriston  Davics  confirms  the  absence  of  the  sense 
of  movement  and  position,  and  found  that  although 
deep   pressure    was   occasionally    appreciated  it  was 


158  INJURIES    OF    NERVES 

badly  localised  on  to  adjacent  sound  parts.  "  Deep 
sensibility  '^  of  tliis  nature  is  probably  due  only  to 
traction  on  surrounding  sound  structures  ;  it  differs 
entirely  from  the  deep  sensibility  seen  after  division 
of  sucli  a  nerve  as  the  median. 

True  deep  sensibility  appears  to  be  absent  in  most 
patients  after  complete  removal  of  the  Gasserian 
ganglion. 

The  mucous  membranes  supplied  by  the  fifth 
nerve  become  insensitive  to  epicritic  and  protopathic 
stimuli.  In  the  mouth  the  area  includes  half  the 
tongue^  as  far  back  as  the  circum vallate  papillge_,  and 
then  i^asses  outwards  along  their  line  to  the  anterior 
pillar  of  the  fauces,  and  then  along  the  anterior 
margin  of  the  soft  palate  to  the  tip  of  the  uvula, 
thence  along  the  centre  of  the  palate  to  the  upper 
lip.  All  on  the  affected  side  of  this  line  lose  sensi- 
bility to  light  touch  and  prick.  The  tongue  retains 
its  deep  sensibility,  the  fibres  conveying  which 
appear  to  travel  by  the  hypoglossal  nerve. 

Gushing  has  confirmed  the  observations  made  by 
Krause,  and  conclusively  shown  that  taste  is  not 
permanently  affected  by  the  removal  of  the  Gasserian 
ganglion.  Morriston  Davies  has  exhaustively  re- 
viewed the  recorded  cases  and  confirmed  these 
observations.  The  fibres  subserving  taste  in  the 
anterior  two  thirds  of  the  tongue  ])ass  in  the  chorda 
tympani,  running  for  a  part  of  its  course  with  the 
lingual    nerve    (vide   also  ^^  Facial    nerve/^  p.    165). 


TESTS    FOR    TASTE  159 

Cusliiiig  offers  tlic  suggestion  that  the  temporary 
loss  of  taste  seen  in  some  cases  after  removal  of  the 
ganglion  may  be  due  to  degenerative  changes  in  the 
lingual  nerve  affecting  the  chorda  tympani,  mechanic- 
ally or  toxically.  Horsley  lias  suggested  that  it 
might  be  due  to  the  unilateral  furring  of  the  tongue^ 
so  often  seen  after  this  operation. 

It  is  by  no  means  an  easy  or  rapid  matter  to  test 
taste  perception^  and  before  any  conclusion  is  reached 
with  regard  to  loss  of  taste  the  patient  must  first 
have  been  proved,  before  operation,  to  possess  the 
sense  of  taste  in  the  anterior  two  thirds  of  the 
tongue  ;  it  is  not  unusual  to  find  that  this  is  absent 
in  elderly  people  otherwise  healthy. 

In  testing  it  is  better  to  employ  solutions  than 
solids.  Solutions  of  sugar,  salt,  quinine  and  acetic 
acid  are  used ;  these  are  brushed  on  to  the 
protruded  tongue  with  a  camePs  hair  pencil  or  glass 
rod.  The  tongue  must  be  kept  protruded  through- 
out the  test,  and  as  soon  as  the  patient  experiences 
any  taste  sensation  he  should  make  an  agreed  sign. 
The  mouth  must  be  well  washed  out  between  each 
application. 

The  nasal  mucous  membrane  on  the  affected  side 
is  anaDsthetic,  hence  the  inhalation  of  irritating  sub- 
stances causes  no  discomfort  or  kichrymation,  and 
tickliu"'  the  affected  nostril  does  not  cause  sneezinsf. 
The  sense  of  smell  may  be  defective  owing  to  dryness 
of  the  mucous  membrane. 


160  INJURIES    OF    NERVES 

Motor  symptoms. — Complete  division  of  the  fifth 
nerve  or  its  motor  division  produces  paralysis  of  the 
muscles  of  mastication^  the  masseter,  temporal  and 
pterygoids.  But  this  causes  little  inconvenience, 
difficulty  in  mastication  being  more  due  to  the  food 
lodging  between  the  cheek  and  gum  owing  to  their 
anaesthesia.  On  opening  the  mouth  the  jaw  is 
deflected  to  the  paralysed  side  from  the  unopposed 
action  of  the  sound  external  pterygoid.  The 
paralysis  of  the  anterior  belly  of  the  digastric  and 
the  mylo-hyoid  muscles,  said  to  be  supplied  from  this 
nerve,  cannot  be  detected  clinically. 

Considerable  difference .  of  opinion  has  existed 
with  regard  to  the  motor  supply  of  the  muscles  of 
the  palate,  and  it  has  been  stated  that  they,  or 
perhaps  the  tensor  palati  only,  are  supplied  by  the 
fifth  nerve.  Gushing  observed  in  four  of  his  cases 
an  asymmetry  of  the  palate  of  a  greater  degree 
than,  in  his  opinion,  could  be  accounted  for  by 
deflection  of  the  jaw.  In  one  case,  also,  he  was  able 
to  obtain  twitches  in  the  corresponding  side  of  the 
soft  palate  on  stimulating  the  stump  of  the  third 
division  of  the  fifth  during  the  course  of  a  ganglion 
extirpation.  On  the  other  hand,  Horslcy  was  able  to 
detect  no  movements  on  similar  electrical  stimulation 
in  three  patients.  Krause  was  of  opinion  that  no 
alteration  of  the  soft  palate  was  to  be  seen,  and 
Morriston  Davies,  from  the  examination  of  twenty- 
six  cases,  found  a  slight  inequality  in  five,  and  came 


MOTOR  SUPPLY  OF  PALATE     IGl 

to  the  conclusion  that  "  the  balance  of  evidence 
seems  to  show  that  the  fifth  nerve  has  nothing  what- 
ever to  do  with  the  nerve  supply  of  the  palatal 
muscles/^  It  is  quite  possible  that  the  asymmetry 
observed  was  due  to  a  loss  of  muscle  sense.  To 
obtain  conclusive  evidence  electrical  examination  of 
the  muscles  is  necessary. 

The  innervation  worked  out  by  Hughlings  Jack- 
son, Aldren  Turner,  Beevor  and  others,  from  the 
accessory  portion  of  the  vagus,  corresponds  with 
clinical  observations.  In  the  few  cases  that  I  have 
had  the  opportunity  of  examining,  no  alteration  was 
present  in  the  palatal  muscles.  Their  motor  supplj^ 
is  through  the  pharyngeal  plexus. 

Paresis  of  the  facial  muscles  has  been  noticed 
after  excision  of  the  ganglion,  due  to  loss  of  the 
sense  of  passive  position  and  movement. 

First  division.  —  This  division  may  be  injured 
during  the  course  of  operations  upon  the  frontal 
sinus,  and  may  be  involved  in  disease  in  this 
situation.  It  may  also  suffer  in  fractures  of  the 
anterior  fossa  of  the  skull,  but  the  injury  is  rarely 
complete,  or  of  the  whole  division.  When  involved 
in  disease  of  the  sinus  the  supra-orbital  and  supra- 
trochlear branches  are  affected ;  as  the  result  of 
fractures,  anaesthesia  of  the  cornea  and  conjunctiva 
alone,  followed  by  subsequent  destruction  of  the 
cornea,  has  been  recorded.  Its  nasal  branch  may 
be  affected  in  fractures  of  the  cribriform  plate. 

11 


162  INJURIES    OF    NEEYES 

The  fir?t  division  of  tlio  fiftli  nerve  snpplies  the 
scalp  as  far  back  as  the  mid-point  between  the 
external  occij)ital  protuberance  and  the  nasion^  to- 
gether with  the  conjunctiva  of  both  lids.  Deep 
touch  is  everywhere  present  after  section  of  this 
division. 

After  removal  of  the  whole  ganglion  transient 
changes  in  the  ]3upil  have  been  noticed  ;  immediately 
after  the  operation  it  is  smaller  than  on  the  sound 
side.  Gushing  observed  this  in  eight  cases ;  it 
existed  for  some  weeks  and  was  associated  with  a 
slight  degree  of  enophthalmos.  But  in  none  of  the 
cases  recorded  by  Morriston  Davies  did  it  remain  for 
as  long  as  this.  No  permanent  alteration  of  lach- 
rymal secretion  results. 

It  is  well  known  that  after  injury  of  the  first 
division  of  the  fifth  nerve  changes  may  supervene  in 
the  cornea^  leading  in  some  cases  to  ultimate  loss  of  the 
eye.  It  is  a  rare  condition  and  present  in  only  a 
small  pro|)ortion  of  the  cases. 

Considerable  diiference  of  opinion  exists  with 
regard  to  its  causation.  One  thing  seems  certain:  it 
does  not  arise  spontaneously  in  cases  in  which  the 
ganglion  has  been  completely  removed,  if  care  be 
taken  to  protect  the  eye  from  injury  during  the 
course  of  the  operation  and  the  succeeding  few  days. 
But  in  cases  of  incomplete  division  of  this  branch  it 
may  do  so_,  thus  falling  into  line  with  what  has  been 
said  with  regard  to  ^'  trophic  "  ulcers  elsewhere  {vide 


CORXf]AL    f'HANGES  1G3 

p.  31).  In  most  of  the  cases  it  has  been  noticed 
daring  the  first  few  days  following-  operation — a 
period  at  which  there  is  a  diminution  of  lachrymal 
secretion.  The  change  begins  in  the  corneal  epi- 
thelium, the  cornea  becomes  dull  and  its  epithe- 
lium is  shed,  infection  rapidly  ensues  and  the  eye 
is  lost. 

Willibrandt  and  Sanger  have  suggested  that 
it  is  due  to  irritation  of  the  peripheral  end  of  the 
nerve,  and  this  theory  has  the  support  of  Parsons. 
But  it  is  obviously  untenable  in  cases  of  complete 
division,  unless  arising  within  a  very  short  time  after 
the  operation,  while  the  fibres  in  the  peripheral  end 
still  conduct  impulses.  I  am  more  in  agreement 
with  the  experimental  work  of  Turner,  Ferrier  and 
Hanau  that  the  corneal  change  is  due  to  external 
injuries  in  all  cases  in  which  the  ganglion  has  been 
completely  removed,  or  the  first  division  completely 
divided. 

Second  and  third  divisions. — These  are  rarely 
affected.  They  may  be  injured  in  fractures  of 
the  petrous  bone  traversing  the  cavum  Meckelii ; 
the  infra  -  orbital  nerve  may  suifer  in  fractures 
of  the  upper  jaw,  or  be  involved  in  growths 
or  inflammatory  affections  of  the  antrum  of  High- 
more.  The  inferior  dental  nerve  suffers  occasionally 
in  fractures  of  the  jaw,  and  the  lingual  nerve  has 
been  injured  in  extraction  of  an  impacted  wisdom 
tooth. 


164  IN.JUEIES    OF    NEEYES 

Tlip  loss  of  epici'itic  and  protopatliic  sensibility 
resulting  from  injury  of  either  of  these  divisions  or 
nerves  is  small ;    deep  sensibility  is  unaffected. 

Facial  nerve.  —  Facial  paralysis  is  one  of  the 
most  common  varieties  of  peripheral  paralysis.  But 
many  of  the  cases  are  incomplete^  and  not^  strictly 
speakings  due  to  injury.  In  265  cases  of  facial 
paralysis  collected  by  Bernhardt^  only  5  or  6  per 
cent,  were  due  to  injury^  and  6  to  9  to  middle- 
ear  disease  ;  the  remainder  belonged  to  the  so-called 
'^  rheumatic  ^'  type.  Much  the  same  percentage 
existed  in  the  130  cases  collected  by  Philip  and  the 
135  of  Hiibschmann.  But  these  figures  by  no  means 
show  the  importance  of  the  surgery  of  the  facial 
nerve,  for  many  cases  due  to  non-traumatic  causes 
come  later  under  the  care  of  the  surgeon. 

Facial  paralysis  is  occasionally  seen  in  the  newly 
born,  usually  in  cases  in  which  forceps  have 
been  necessary ;  Lib  in  found  facial  paralysis  25 
times  in  1063  forceps  deliveries.  It  is  usually 
unilateral. 

Symptoms. — The  symptoms  caused  by  interference 
with  the  functions  of  the  facial  nerve  differ  according 
to  the  level  of  the  injur}",  and  fall  into  three  groups 
owing  to  the  association  with  it  of  the  chorda  tym- 
pani  nerve  between  the  geniculate  ganglion  and  the 
lower  part  of  the  Fallopian  canal ;  here  it  leaves  the 
facial  to  cross  the  tympanic  cavity. 

Injury    to   the   facial   nerve    below    the   point    at 


FACIAL    PARALYSIS  165 

which  the  chorda  leaves  it  results,  most  often,  from 
penetrating  wounds  of  accidental  or  operative  origin 
in  the  parotid  and  sub-maxillary  regions ;  it  also 
occurs  as  a  birth  paralysis. 

Its  complete  division  produces  flaccid  paralysis  of 
all  the  muscles  of  the  corresponding  side  of  the  face, 
and  is  at  once  obvious.  The  natural  furrows  are 
obliterated,  leaving  the  affected  side  of  the  face, 
expressionless  and  devoid  of  voluntary  or  emotional 
movement.  The  eye  cannot  be  closed  and  the  lower 
lid  droops,  allowing  the  ]3unctum  to  fall  away  from 
the  eyeball  ;  this,  with  the  loss  of  the  suction 
action  of  the  lachrymal  sac  from  paralysis  of 
Horner^s  muscle,  is  responsible  for  the  lacrymation. 
The  conjunctival  reflex  is  abolished  through  its 
motor  limb.  On  attempting  to  close  the  eye  the 
eyeball  moves  upwards. 

If  completely  divided  where  accompanied  by  the 
chorda  tympani  nerve,  taste  is  lost  over  the  corres- 
ponding half  of  the  anterior  two  thirds  of  the  tongue. 
The  nerve  may  be  injured  in  this  situation  as  the 
result  of  operations  upon  the  middle  ear  or  a  frac- 
ture of  the  petrous  bone,  or  be  affected  in  otitis 
media. 

When  divided  above  the  geniculate  ganglion  the 
symptoms  resemble  those  in  the  first  group,  but  the 
auditory  nerve  is  usually  affected  at  the  same  time. 
It  is  sometimes  stated  that  a  lesion  of  the  facial  in 
this  situation  produces  ]niralysis  of  the  c()rres])o]uliiig 


166  INJURIES    OF    NERVES 

half  uf  tlie  soft  palate  ;  I  have  been  unable  to  observe 
this. 

In  patients  in  whom  the  facial  paralysis  has 
existed  for  some  time^  contractures  of  the  affected 
muscles  may  develop.  This  may  cause  momentary 
confusion  and  difficulty  in  diagnosis^  the  healthy  side, 
at  rest,  appearing  to  be  the  affected ;  voluntary  move- 
ment at  once  reveals  the  side  paralysed. 

In  investigating  a  case  of  facial  paralysis,  its 
cause,  the  site  of  the  injury,  and  the  degree  of  in- 
volvement of  the  nerve  must  be  discovered.  The 
cause  is,  as  a  rule,  obvious,  and  shoAvn  by  the  history 
of  injury  or  operation. 

Prognosis. — The  prognosis  varies  with  the  cause  of 
the  injury.  A  very  large  proportion  of  the  idio- 
pathic cases  recover  spontaneously,  a  few  only  of 
the  so-called  rheumatic  type  remaining  permanently 
paralysed  and  needing  operative  interference.  The 
electrical  reactions  are  of  the  utmost  importance. 
Complete  facial  paralysis  may  entirely  disappear  in  a 
few  days  or  weeks,  or  remain  permanent.  There  is 
nothing  except  the  investigation  of  the  electrical 
reactions  of  the  affected  muscles  which  will  enable  a 
prognosis  to  be  given.  If  the  reactions  are  those  of 
incomplete  division  recovery  may  be  confidently 
expected.  If  the  true  reaction  of  degeneration  is 
present,  recovery  apart  from  operation  is  unusual. 
In  most  instances  the  injury  is  incomplete  and 
operation    is    rarely     indicated.        Facial    paralysis. 


TREATMExVT    OF    FACIAL    PARALYSIS  167 

following  an  operation  on  the  middle  ear  is,  as  a  rule, 
due  to  incomplete  division  ;  recovery  takes  place  in 
the  majority  of  the  cases.  In  facial  paralysis  com- 
plicating fracture  of  the  base  of  the  skuli,  whether 
the  involvement  is  primary  or  secondary,  recovery 
usually  takes  place.  The  partial  facial  paralysis, 
paralysis  of  the  lower  facial  muscles,  which  is  so 
common  as  the  result  of  operations  in  the  submaxillary 
region,  is  rarely  permanent;  if  apposition  of  the 
edges  of  the  wound  is  accurate  and  the  wound  heal 
without  suppuration,  recovery  is  the  rule. 

Treatment. — The  lines  upon  which  the  treatment 
of  facial  paralysis  is  conducted  differ  not  at  all  from 
those  laid  down  in  Chapters  Yl  and  VII. 

If  the  nerve  be  completely  divided  primary  suture 
should  be  carried  out,  if  possible,  but  for  anatomical 
reasons  this  is  often  impossible.  In  older  cases 
continuity  with  the  central  nervous  system  must  be 
restored  either  by  means  of  its  own  central  end,  or 
more  often  for  anatomical  reasons,  by  anastomosis. 
When  the  nerve  is  involved  as  the  result  of  middle- 
ear  disease  operative  interference  in  the  antrum  or 
tympanum  is  indicated. 

If  the  facial  nerve  has  been  completely  divided  in 
the  petrous  bone,  whether  as  the  result  of  operation 
or  fracture,  the  sooner  operation  is  carried  out  the 
better  the  chance  of  complete  recovery.  AV^hen  the 
injury  follows  a  mastoid  operation  time  must  be 
allowed    to    permit   all   inflammation  to   cease ;   it  is 


168  INJURIES    OF    NERVES 

unjustifiable  to  perform  a  plastic  operation  on  nerves 
involving  a  deep  dissection  in  the  neck  while  a 
suppurating  wound  is  present  behind  the  ear. 

If  the  reaction  of  degeneration  develops  in  a  case 
of  idiopathic  facial  paralysis,  spontaneous  recovery  is 
unlikely,  but  it  is  justifiable  to  wait  for  six  months 
before  resorting  to  the  operation  of  anastomosis. 

In  the  large  proportion  of  cases  submitted  to 
operation  end-to-end  union  is  out  of  the  question, 
and  a  neighbouring  nerve  must  be  utilised.  This 
was  first  done  by  Drobnik  in  1879  ;  he  divided  the 
spinal  accessory  nerve  and  united  its  central  end 
with  the  peripheral  end  of  the  divided  facial.  But 
the  modern  operation  for  facial  paralysis  is  due  to 
the  initiative  of  Ballance,  who  first  carried  out  the 
modern  operation  in  1895.  In  a  boy,  aged  eleven 
years,  six  months  after  injury  in  a  mastoid  operation, 
he  anastomosed  the  facial  nerve  to  the  spinal  acces- 
sory. It  is  from  the  time  of  the  Ballances  and 
Purves  Stewart^s  paper,  published  in  1903,  that  the 
present  interest  in  the  subject  dates. 

Different  nerves  have  been  recommended  and 
used,  and  nerve  crossing  employed  as  well  as  anas- 
tomosis. We  have  to  consider  what  operation  on 
what  nerve  will  most  quickly  restore  the  power  of 
dissociated  movement  to  the  paralysed  muscles  Avith 
the  least  damage  to  the  sound  nerve  used. 

The  hypoglossal  is  the  nerve  of  choice ;  dissociated 
voluntary  movement  is  restored  much  more  quickly 


FACIO-HYPOGLOSSAL    ANASTOMOSIS  169 

than  when  the  spinal  accessory  is  employed.  Nerve 
anastomosis  and  not  nerve  crossing  should  be  carried 
out.  It  is  unnecessary  to  sacrifice  a  sound  nerve, 
emotional  movement  may  bo  restored  without.  The 
complete  peripheral  operation  should  be  performed, 
and  nerve-fibres  divided  in  the  sound  nerve,  either 
by  making  an  oblique  cut  into  the  nerve,  or  by 
splitting  off  a  portion  and  uniting  it  end-to-end  with 
the  peripheral  end  of  the  facial  {vide  p.  91). 

Instances  of  recovery  have  been  recorded  after 
simply  inserting  the  peripheral  end  of  the  facial 
into  a  vertical  slit  in  the  hypoglossal,  but  the  return 
of  voluntary  movement  is  more  rapid  if  axis 
cylinders  are  definitely  divided. 

The  primary  essential  for  success  in  this  operation 
is  asepsis.  If  the  Avound  suppurates  recovery  will 
be  delayed  and  imperfect.  The  greatest  care  and 
gentleness  of  handling  is  necessary,  and  the  incisions 
must  be  made  into  the  nerve  with  a  sharp,  thiii- 
bladed  tenotomy  knife. 

In  order  to  carry  out  the  operation  of  facio- 
hypoglossal  anastomosis  a  long  incision  should  be 
made  extending  from  the  mastoid  at  the  level 
of  the  external  auditory  meatus  down  to  the  great 
cornu  of  the  hyoid  bone.  The  anterior  border 
of  the  sterno-mastoid  muscle  is  first  defined  and 
pulled  backwards,  then  the  posterior  belly  of  the 
digastric  identified  and  pulled  backwards  and  down- 
wards j   if  large,  it  may  be  necessary  to  divide   some 


170  INJURIES    OF    NERVES 

of  the  fibres  in  its  upper  border.  The  facial  nerve 
is  next  sought  for;  it  is  most  easily  found  by 
feeling  for  the  styloid  process ;  the  nerve  passes  out 
immediately  in  front  of  this  and  enters  the  parotid 
gland.  The  facial  nerve  should  next  be  freed, 
and  an  attempt  made_,  in  cases  in  which  it  has 
been  injured  in  the  performance  of  a  mastoid 
operation,  to  pull  the  stump  out  from  the  stylo- 
mastoid foramen.  If  this  cannot  be  done  the  nerve 
should  be  divided  in  the  foramen,  as  high  as  possible, 
with  a  tenotomy  knife.  The  hypoglossal  should  next 
be  found  ;  the  transverse  process  of  the  axis  is  first 
felt  and  serves  as  a  guide  to  the  occipital  artery, 
which  runs  upwards  and  outwards  across  it.  The 
internal  jugular  vein  is  identified  and  retracted 
inwards ;  this  exposes  the  vagus  and  the  hypoglossal 
nerves ;  the  latter  is  easily  distinguished  by  its 
relation  to  the  occipital  artery.  After  freeing,  it  is 
brought  towards  the  facial  and  an  oblique  cut  made 
into  its  trunk  so  as  to  divide  about  one  third  of  its 
fibres  and  the  peripheral  end  of  the  facial  sutured  in 
with  fine  catgut.  If  there  is  any  tension  on  the 
junction  it  is  better  to  raise  a  flap  and  perform  end- 
to-end  union.  The  raw  surface  left  and  the  junction 
should  be  surrounded  with  Cargile  membrane. 

The  after-treatment  requires  care.  The  nutrition 
of  the  muscles  must  be  kept  up  by  massage  and 
stimulation  with  the  constant  current  until  voluntary 
power    is    restored.      As    soon    as    voluntary   power 


RECOVERY   AFTER    ANASTOMOSIS     171 

returns  to  each  group  of  muscles  they  must  be 
exercised  systematically  until  the  patient  regains 
complete  control. 

An  operation  such  as  I  have  described  inflicts 
astonishingly  little  injury  on  the  hypoglossal  nerve. 
At  first  there  may  be  paralysis  of  the  corresponding 
half  of  the  tongue^  but  if  the  wound  heal  by  first  inten- 
tion it  is  quite  transient^  and  the  slight  hemiatrophy 
which  supervenes  disappears  in  a  few  months. 

No  improvement  in  the  condition  of  the  facial 
muscles  is  to  be  expected  for  at  least  six  or  eight 
weeks.  Abont  this  time  it  is  usually  noticed  that 
the  lower  part  of  the  face  at  rest  is  more  sym- 
metrical ;  following  this^  from  three  to  six  months 
after  o23eration,  a  return  of  power  in  the  muscles 
at  the  angle  of  the  mouth  takes  place  ;  those  which 
regain  voluntary  poAver  last  are  the  muscles  around 
the  eye  and  the  frontalis.  Preceding  the  return 
of  voluntary  power  the  muscles  show  a  change  in 
their  electrical  reactions,  the  reaction  described  as 
typical  of  incomplete  division  developing.  In  some 
cases,  particularly  in  those  following  an  operation  for 
acute  mastoiditis,  recovery  may  be  much  delayed. 

Movement  is  at  first  associated  with  movements  of 
the  tongue,  but  soon  becomes  dissociated.  In  a 
favourable  case  the  patient  should  be  able  to  perform 
all  movements  in  from  nine  months  to  a  year,  but 
emotional  movement  is  restored  much  later.  It  is  at 
this   stage   that   the   patient   is   able    voluntarily    to 


172  mJUEIES    OF    NERVES 

throw  all  the  muscles  of  his  face  into  action,  yet  in 
smiling  the  affected  side  of  the  face  remains  motion- 
less. Emotional  movement  may  take  years  to  be 
restored,  but  improvement  steadily  ensues  and  may 
be  expected  to  be  perfect  in  a  young  patient  in  whom 
the  wound  healed  by  first  intention. 

After  facio-hypoglossal  anastomosis  the  return  of 
power  is,  therefore,  as  follows  :  First,  movements 
associated  with  those  of  the  tongue,  then  dissociated, 
and  finally  emotional.  In  all  the  cases  of  facial 
nerve  anastomosis  reported  sufficiently  long  after 
operation,  some  recovery  took  place  ;  this  commenced 
earlier  and  became  more  complete  in  cases  in  which  the 
hypoglossal  nerve  was  used,  but  up  to  the  present 
few  cases  of  ijerfect  recovery  have  been  recorded. 

In  any  case  we  can  confidently  predict  great 
improvement  to  follow  the  operation,  which  may  in 
time  restore  the  condition  of  the  face  to  normal. 

Auditory  nerve. — This  nerve  is  usually  injured  in 
fractures  of  the  middle  fossa  of  the  skull,  and  is 
associated  in  80  per  cent,  of  the  cases  with  a  facial 
paralysis. 

Nerve  deafness  results  from  its  complete  division. 

Glosso-pharyngeal  nerve. — No  instance  of  isolated 
injury  to  this  nerve  has  been  recorded.  It  is  most 
likely  to  suffer  at  the  jugular  foramen,  with  the 
vagus  and  spinal  accessory  nerves.  But  although 
fractures  of  the  base  of  the  skull  frequently  involve 
this  region,  the  nerves  usually  escape. 


VAGUS    NERVE  173 

Tlie  symptoms  produced  b}'  its  injury  arc  :  diffi- 
culty in  swallowing  from  paralysis  of  the  middle 
constrictor  and  stylo-pharyngeus  muscles^  and  loss  of 
sensibility  on  the  posterior  third  of  the  tongue  and 
pharynx  on  the  affected  side. 

Vagus  nerve. — The  vagus  during  its  long  course 
through  the  neck  is  exposed  to  many  forms  of  in- 
jury, but  rarely  suffers  complete  division.  It  or 
its  recurrent  laryngeal  branch  may  be  injured  in 
operations  upon  the  thyroid  gland,  ligature  of  the 
great  vessels,  or  removal  of  tuberculous  or  malignant 
glands.  It  may  suffer  in  the  thorax  as  the  result  of 
the  pressure  of  growths  or  aneurysms. 

It  was  the  belief  of  the  older  surgeons  that  death 
invariably  resulted  from  division  of  one  vagus 
nerve,  but  if  it  is  divided  below  the  point  at  which 
the  recurrent  laryngeal  nerve  is  given  off,  no  symp- 
toms are,  as  a  rule,  present,  hence  the  surgeon  should 
not  hesitate  to  sacrifice  the  nerve  if  necessary  in 
operations  upon  malignant  disease.  In  twenty-four 
cases  in  which  the  nerve  has  been  divided  durino- 
the  course  of  operations  in  no  instance  did  death 
result  from  the  nerve  injury.  Thus,  in  a  case 
recorded  by  Rivington,  the  nerve  was  divided  during 
the  operation  of  ligature  of  the  internal  carotid.  No 
symptoms  resulted,  and  when  death  occurred  later 
from  a  cerebral  abscess  the  division  was  verified. 

But  when  irritated  during  the  course  of  operations, 
included   in   a    ligature,  pulled  upon   by   retractors. 


174  INJURIES    OF    NERYES 

picked  up  in  .pressure  forceps^  etc.,  alarming  sym- 
ptoms may  result.  In  cases  recorded  by  Michaux 
and  Tilman  the  pulse  and  respiration  temporarily 
ceased  from  sudden  stimulation  of  the  vagus  during 
the  course  of  operations  upon  the  neck. 

This  nerve  carries  the  motor  fibres  to  the  muscles 
of  the  soft  palate  and  larynx.  The  paralysis  of  the 
palate  is  easily  recognised  if  the  patient  is  told  to 
open  the  mouth  and  the  raphe  of  the  palate  be 
watched;  it  is  seen  to  be  pulled  to  the  sound  side 
when  elevated  by  producing  such  sounds  as  ^^  eh." 

Hoarseness  results  from  paralysis  of  one  recurrent 
laryngeal  nerve.  On  laryngoscopic  examination  the 
cord  of  the  affected  side  is  seen  to  be  fixed  midway 
between  adduction  and  abduction — the  cadaveric 
position. 

In  investigating  a  case  of  paralysis  of  the  larynx, 
due  to  an  injury  to  the  vagus  nerve  or  its  recurrent 
branch,  it  is  necessary  to  discover,  if  possible,  the 
seat  of  the  injury.  The  condition  of  the  palate  is 
first  investigated  ;  if  this  is  not  affected  the  history 
of  operation  or  the  symptoms  of  growth  will  alone 
reveal  the  seat  of  the  injury. 

Treatment  is  carried  out  along  the  usual  lines, 
primary  or  secondary  suture,  or  if  this  is  impossible, 
anastomosis  to  cervical  nerves  or  spinal  accessory. 

Spinal  accessory  nerve.— This  nerve  supplies  the 
sterno-mastoid  and  the  trapezius  in  conjunction  with 
branches  from  the  cervical  plexus.      The  extent  of 


PARALYSIS    OF    TRAPEZIUS  175 

the  suppl}'  of  the  trapezius  from  the  spinal  acces- 
sory varies,  Init  as  a  rule  the  upper  part  is  supplied 
bv  this  nerve,  the  lower  bv  branches  from  the  third 
and  fourth  cervical  nerves.  The  spinal  accessory  is 
most  often  injured  during  the  operation  of  removal 
of  tuberculous  glands  of  neck,  and  in  many  of  the 
cases  the  branches  of  the  third  and  fourth  cervical 
are  also  affected  and  paralysis  of  the  whole  trapezius 
results.  It  must  not  be  foro-otten  that  the  nerve 
may  be  involved  in  the  spinal  canal  and  at  the 
jugular  foramen,  though  in  the  latter  position  it  is 
rarely  affected  alone. 

Division  of  the  nerve  in  the  anterior  triangle  of 
the  neck  produces  paralysis  of  the  sterno-mastoid 
and  upper  part  of  the  trapezius.  The  paralysis  of 
the  sterno-mastoid  gives  rise  to  no  marked  symptom. 
There  is  no  alteration  in  the  position  or  movements 
of  the  head,  but  the  muscle  does  not  become  promi- 
nent on  depressing  the  head  against  resistance,  or  on 
rotating  it  to  the  opposite  side.  The  upper  fibres  of 
the  trapezius  muscle  usually  suffer  alone  when  the 
nerve  is  divided  in  this  situation.  This  produces  an 
alteration  in  the  contour  of  the  neck  (vicle  infra), 
slight  drooping  and  rotation  of  the  shoulder,  but 
little  interference  with  movement. 

Paralysis  of  the  whole  trapezius  muscle  produces 
considerable  deformity  and  disability,  and  the 
greatest  care  should  be  taken  to  avoid  this  result  of 
operations  upon  the   neck.      The  patient    complains 


176  INJURIES    OF    NERVES 

of  weakness  of  the  whole  upper  limb.  The  scapula  is 
dropped  and  rotated  forwards  (vide  Plates  IV  and  V), 
and  so  tilted  that  its  spine  is  more  horizontal 
than  normal  and  its  lower  angle  is  nearer  the  mid- 
line than  the  upper.  There  is  also  slight  winging 
of  the  scajDula,  which  disappears  at  once  on  bring- 
ing the  serratus  magnus  muscle  into  action  {vide 
p.  212). 

The  lower  border  of  the  rhomboideus  major  stands 
out  prominently  and  becomes  more  marked  when  the 
shoulders  are  thrown  back.  The  contour  of  the  neck 
is  altered  and  becomes  somewhat  irregular  from  the 
exposure  of  the  levator  anguli  scapulae.  The  patient 
is  unable  to  raise  the  arm  above  the  head  after  it 
has  been  abducted  by  the  deltoid,  but  can  raise  it 
above  the  head  in  front  of  the  body,  and  this  may 
lead  to  difficulty  in  diagnosis.  When  the  paralysis 
of  the  trapezius  has  been  in  existence  for  some  time 
the  patient  may  learn  to  raise  the  arm  above  the 
head  by  a  peculiar  manoeuvre.  The  arm  is  abducted 
by  the  deltoid  muscle  and  then  carried  a  little 
forward  and  rotated  outwards  by  the  pectoralis 
major  and  carried  above  the  head  in  this  position  by 
the  serratus  magnus. 

Immediate  suture  should  be  carried  out  in  all 
cases  in  which  the  nerve  is  divided  during  the  course 
of  an  operation.  If  not  seen  until  later,  an  attempt 
should  be  made  to  perform  secondary  suture.  If  it 
is  impossible  to  find  the  central  end  or  to  bring  the 


PLATE    lY. 

Taken  from  a  patient  witli  paralysis  of  tlie  whole  trapezius  following 
an  extensive  operation  upon  tnbercnlovis  cervical  glands. 


FiGi^.  1. — The  prominence  formed  by  the  rliomboideus  major  and  the 
droi)ping  and  tilting  of  the  scapnla  are  well  shown. 


Fig.  2. — Shows  the  alteration  in  the  contour  of  the  neck. 
To  face  p.  17G.  Adlard  ^-  Son,  Impr. 


PLATE    Y. 

From  the  same  patient  as  Plate  IV. 


Fig.  1. — The  forward  tiltino-  of  the  shoulder  as  seen  from  the  side. 


Fig.  2. — Sound  side  for  comparison. 

To  face  p.  170.  Adlard  .y  Son,  Impr. 


HYPOGLOSSAL    NERVE  177 

ends  into  apposition  tliu  periplicral  end  should  be 
anastomosed  to  the  anterior  primary  divisions  of  the 
third  or  fourth  cervical  nerves. 

Hypoglossal  nerve. — This  nerve  is  rarely  injured. 
It  has  been  severed  most  often  as  the  result  of  gun- 
shot wounds  and  surgical  operations.  It  may  be 
pressed  upon  by  a  growth  extending  deeply  into 
the  pterygoid  region,  but  in  these  cases  the  muscles 
of  the  palate  and  pharynx  suffer  as  well. 

The  symptoms  are  characteristic  :  the  affected  half 
of  the  tongue  is  flaccid,  and,  on  protrusion,  is  pushed 
to  the  paralysed  side ;  it  becomes  atrophic  and 
Avrinkled.  At  first  the  paralysis  interferes  consider- 
ably with  mastication,  deglutition  and  articulation, 
but  this  soon  passes  off  and  may  be  little  noticed. 
Purves  Stewart  records  that  "  the  hemi-atrophy 
and  impairment  of  movement  due  to  division  of  the 
hypoglossal  nerve  causes  remarkably  little  incon- 
venience, no  more  than  a  transient  awkwardness  in 
mastication,  articulation  and  deglutition.^^ 


12 


CHAPTER   XII 

Cervical  Plexus  :  Method  of  Injury  ;  Loss  of  Sensibility  produced 
by  Injury  to  Sensory  Brandies  ;  Injury  to  Motor  Branches — 
Phrenic  Nerve — Cervical  Sympathetic. 

The  cervical  plexus  formed  by  the  anterior  primary 
divisions  of  tlie  upper  four  cervical  nerves  rarely 
suffers  injury  except  as  the  result  of  operative  pro- 
cedures. In  extensive  operations  in  the  posterior 
triangle  of  the  neck  its  sensory  branches  are  not 
infrequently  divided.  These  are^  the  small  occipital, 
great  auricular  and  transverse  cervical  from  the 
second  and  third,  and  the  descending  cervical  from 
the  third  and  fourth  anterior  primary  divisions. 

Loss  or  alteration  in  sensibility  in  the  areas 
supplied  by  these  nerves  is  common,  and  will 
usually  be  found  after  extensive  neck  operations, 
but  rarely  gives  rise  to  trouble,  and  is  still  less  often 
permanent  when  the  edges  of  the  wound  have  been 
brought  into  apposition  accurately  and  healing  has 
taken  place  by  first  intention. 

The  branches  may  be  injured  alone  or  together; 
the  latter  is  the  more  common.  The  descending 
branches    suffer   most   often   alone ;    the    extent    to 


To  illustrate  the  loss  of  sensibility  produced  by  section  of  the  sensory 
nerves  of  the  cervical  plexus.     Modified  from  Gushing. 

To  face  p.  179.  Adlard  S,-  Son,  Impr.. 


PHRENIC    XERVJO  179 

wliicli  these  brandies  descend  should  be  noted 
(Plcitc  YI). 

W.hen  divided  during  the  course  of  an  operation 
primary  suture  should  be  performed,  as  considerable 
discomfort  may  result  from  non-union. 

The  most  important  motor  branch  of  the  plexus  is 
the  phrenic,  which  arises  mainly  from  the  fourth 
cervical,  but  receives  in  most  cases  a  branch  from 
either  the  third  or  fifth  ;  other  branches  are,  to  the 
levator  anguli  scapulas  and  scalenus  medius  from  the 
third  and  fourth  ;  the  sterno-mastoid  and  trapezius 
receive  branches  respectively  from  the  second  and 
third  and  the  third  and  fourth  in  common  Avith  those 
given  from  the  spinal  accessory.  These  have  been 
considered  with  the  spinal  accessory  nerve. 

Phrenic  nerve. — This  nerve  may  be  injured  as  it 
lies  on  the  scalenus  medius  during  the  progress  of 
operations  upon  lymphatic  glands  or  upon  the  supra- 
clavicular portion  of  the  plexus.  It  has  been 
injured  most  often  during  the  operation  of  ligature 
of  the  third  part  of  the  subclavian  artery,  being 
included  in  the  ligature  or  divided.  In  one  case 
recorded  by  Bransby  Cooper  violent  coughing  set 
in  immediately  after  the  o2:)eration,  and  continued 
until  death  on  the  iifteenth  day  following  inclusion 
of  the  nerve  in  a  ligature.  Erichsen  and  Keidel 
also  published  cases  in  which  death  followed  a  few 
days  after  division  of  this  nerve,  death  being  due  to 
pulmonary  troubles. 


180  INJURIES    or    NERVES 

If  both  phrenic  nerves  are  injured  respiration  is 
carried  out  entirely  by  means  of  the  extei'nal 
respiratory  muscles.  No  symptoms  may  be  present 
while  the  patient  is  at  rest^  but  dyspnoea  is  marked 
on  exertion.  On  watching  the  movements  of  the 
abdomen  and  chest  it  is  seen  that  the  abdomen  re- 
tracts on  inspiration  and  is  forced  out  on  expiration — 
the  exact  opposite  of  the  normal  movements.  When 
injured  on  one  side  only,  the  paralysis  is  little 
noticeable,  but  careful  inspection  will  show  the 
impairment  of  movement  on  the  affected  side.  X- 
ray  examination  will  demonstrate  the  deficient  move- 
ment of  the  diaphragm. 

The  prognosis  is  good  :  few  cases  have  succumbed 
to  the  immediate  result  of  division  of  one  phrenic 
nerve. 

Immediate  suture  should  be  carried  out  in  all 
cases  in  which  the  nerve  has  been  accidentally 
divided  during  the  course  of  an  operation. 

Cervical  sympathetic— The  cervical  sympathetic 
may  be  affected  as  it  lies  deeply  behind  the  carotid 
sheath,  as  the  result  of  a  penetrating  wound  or 
operation,  or  be  pressed  upon  by  new  growth  or 
involved  in  fibrous  tissue.  Its  white  rami  communi- 
cantes  from  the  anterior  primary  divisions  of  the 
first  and  second  dorsal  nerves  may  be  injured, 
especially  in  traction  injuries  of  the  brachial  plexus ; 
it  usually  suffers  when  the  whole  plexus  is  injured 
and  in  the  lower  arm  type  of  lesion. 


PLATE   YII. 


From  a  patient  who  completely  ruptured  the  left  brachial 
plexus  as  the  result  of  a  fall  on  the  point  of  the  shoulder. 
The  pseudo-ptosis  and  slight  enophthalmos  are  well  seen. 


To  face  p.  181. 


Adlard  ^  Son,  Impr. 


CERVICAL    SY:\rPATHETIC  181 

It  must  not  be  forgotten  that  the  pupillary  fibres 
may  be  injured  in  the  spinal  cord  itself. 

The  pupillary  changes  seen  after  injuries  of  the 
cervical  sympathetic  were  recorded  first  by  Petit  in 
1727,  but  the  earliest  complete  description  appears  to 
have  been  due  to  Jonathan  Hutchinson^  who^  in  1866, 
described  the  effects  of  its  injury  with  the  plexus  in 
a  stab  wound  of  the  neck,  and  of  its  pupil  dilating 
fibres  in  injuries  of  the  spinal  cord. 

It  is  by  means  of  the  fibres  supplying  the  eye  and 
orbital  muscles  that  affections  of  this  part  of  the 
sympathetic  are  recognised.  It  carries,  in  addition, 
vaso-motor  fibres  for  the  blood-vessels  of  the  face 
and  upper  limb,  and  fibres  for  the  suppl}^  of  the 
sweat  glands. 

Section  of  the  cervical  sympathetic  produces  slight 
enophthalmos  and  pseudo-ptosis  (vide  Plate  Yll)  ; 
the  upper  lid  droops  but  can  be  elevated  spontane- 
ously. The  jDupil  affected  is  smaller  than  the  sound, 
unless  seen  in  a  bright  light,  when  both  are  equal 
and  contracted.  It  does  not  dilate  when  shaded,  or 
in  response  to  the  instillation  of  cocaine  or  to 
pinching  the  side  of  the  neck  (cilio-spinnl  reflex). 
The  affected  side  of  the  face  does  not  flush  or  sweat 
and  the  ear  often  feels  colder  to  the  touch  of  the 
observer  than  the  sound  one.  The  area  of  absence 
of  sweating  includes,  as  first  pointed  ont  b}'  Purves 
Stewart,  the  whole  of  the  upper  limb  ;  this  1  have 
been  al)le  to  confirm.  No  interference  with  the 
heart's  action  has  been  recorded. 


182  IX.JURTE8    OF    NERVES 

Stimulation  of  the  sympathetic  much  more  rarely 
comes  under  the  care  of  the  surgeon  ;  it  may  occur 
as  the  result  of  the  pressure  of  tumours  or  aneurysms 
or  the  traction  of  adhesions.  It  results  in  exoph- 
thalmos^ widening  of  the  jDalpebral  fissure^  dilatation 
of  the  pupil_,  Avith^  in  many  cases^  flushing  and 
sweating. 

The  prognosis  will  depend  upon  the  cause  of  the 
injury.  Occurring  in  connexion  with  injuries  of  the 
brachial  plexus  it  is  rarely  complete;  the  eye_,altliougli 
remaining  contracted  on  shadings  dilates  to  the 
instillation  of  cocaine.  These  cases  usually  recover. 
If  the  paralysis  is  complete,  recovery  is  unlikely 
when  injured  in  association  with  the  brachial  plexus, 
its  treatment  under  tliis  condition  is  impossible  for 
anatomical  reasons. 

Its  division  in  the  neck  should  be  treated  by 
primary  or  secondary  suture.  The  work  of  Langley 
and  Anderson  has  established  the  fact  that  the 
preganglionic  fibres  of  the  sympathetic  regenerate 
just  as  peripheral  nerves.  If  the  ends  cannot  be 
brouglit  into  apposition  nerv^e  anastomosis  may  be 
carried  out. 


CHAPTER   XIII 

The  Bracliial  Plexus :  Distribution  of  its  Roots  to  Muscles  and 
Skin — Classification  and  Causation  of  its  Injuries— Injuries 
to  Whole  Plexus  ;  Upper  Arm  Type ;  Lower  Arm  Type  ; 
Inner  Cord  ;  Outer  Cord ;  Posterior  Cord — Treatment  and 
Prognosis  of  Brachial  Plexus  Injuries — Eracliial  Birth 
Paralysis. 

Under  the  term  "  brachial  plexus ''  is  included  the 
anterior  primary  divisions  of  the  fifth^  sixth^  seventh 
and  eighth  cervical  nerves,  with  varying  portions  of 
the  first  dorsal  and  fourth  cervical,  together  with 
the  trunks  and  cords  formed  by  their  junction  and 
decussation.  The  individual  named  nerves  arising 
from  these  are  not  included. 

A  knowledge  of  the  motor  distribution  of  the 
various  roots  entering  into  tlie  plexus  is  necessary  in 
order  to  understand  the  paralysis  resulting  fi-om 
injuries. 

Although  fibres  from  more  than  one  root  can  be 
traced  to  most  of  the  muscles  of  the  up]3er  limb,  from 
the  clinical  standpoint  the  motor  supply  depends 
usually  upon  one  root  only. 

Stimulation  of  the  anterior  primary  divisions 
during  the  course  of  operations,  and  the  investiga- 
tion of  the  motor  affection  I'osultino*  from  accidental 


184  INJURIES    OF    XEEVES 

lesions_,  the  exact  nature  of  wliicli  is  made  manifest  by 
operation^  are  the  means  by  which  the  extent  of  their 
supply  is  elucidated.  These  opportunities  arise  most 
often  in  injuries  of  the  upper  and  lower  roots^  rarely 
in  those  of  the  middle  of  the  series  ;  the  distribution 
of  these  latter  is,  therefore,  somewhat  uncertain. 

Much  more  difficulty  and  considerable  confusion 
exists  with  reo^ard  to  the  sensory  distribution  of  the 
posterior  roots  entering  into  the  formation  of  the 
plexus,  on  account  of  the  different  methods  which 
have  been  used.  It  is  very  necessary  to  bear  in 
mind  the  distinction  between  areas  of  full  and 
exclusive  supply  [vide  p.  15),  and  also  to  separate 
the  areas  of  supply  of  the  different  forms  of  sensi- 
bility. The  distribution  of  the  roots  entering  the 
plexus  to  the  skin  of  the  upper  limb  does  not,  of 
course,  correspond  to  the  area  which  would  become 
insensitive  to  cutaneous  stimuli  on  division  of  that 
root.  The  well  known  fio-ures  of  Thorburn  and 
Kocher  were  obtained  by  various  methods,  jDrinci- 
pally  from  instances  of  injury  to  the  spinal  cord, 
others  from  injuries  to  roots,  sometimes  the  full 
supply  being  obtained,  at  others  the  exclusive.  This 
probably  accounts  for  the  difference  seen  in  the 
various  plates.  In  most  cases,  however,  the  areas 
seem  to  be  those  of  the  full  protopathic  supply. 
The  areas  given  by  Dr.  Head,  obtained  from  cases  of 
herpes  zoster,  should  also  correspond  to  the  full 
protopathic  supply.      But  it   has  to  be   remembered 


SUPPLY  OF  POSTERIOR  ROOTS   185 

tliat  the  overlap  betAveen  adjacent  roots  is  consider- 
able in  the  upper  limb  ;  for  example,  it  is  possible  to 
completely  divide  the  anterior  primary  divisions  of 
the  fifth,  sixth  or  seventh  cervical  nerves  containing 
the  cutaneous  fibres  arising  from  the  posterior  roots 


Firj.  11. — Hopresents  the  full  protopathie  supply  of  fifth 
cervical  and  first  dorsal  posterior  roots.  Vertical  shading  : 
fifth  cervical.     Oblique  shadin*^- :  first  dorsal. 

of  the  fifth,  sixth  or  seventh  cervical  nerves,  without 
producing  nny  sensory  loss  that  can  be  discovered 
by  any  of  the  methods  at  our  disposal.  It  is,  there- 
fore, impossible  to  delineate  all  the  areas  supplied  by 
these  roots  on  any  one  chart  of  the  upper  limb. 
The    diagram    given    (Fig.    11)    represents    tlic    full 


186  lA^.JUPJES    OF    NERVES 

protopatliic  supply  of  the  fifth  cervical  and  first 
dorsal  nerves,  but  it  must  be  remembered  that  the 
areas  of  full  supply  of  the  sixth  and  eighth  cervical 
will  overlap  these  considerably.  These  areas  are 
onl}^  of  use  from  the  point  of  view  of  residual 
sensibility  and  in  irritative  conditions  leading  to 
hyperalgesia. 

The  tables  usually  given  illustrating  the  root 
supply  to  the  muscles  of  the  ujoper  limb  have  been 
obtained,  not  only  from  injuries  to  nerves,  but  also 
from  injuries  to  the  spinal  cord.  The  following- 
table  differs  from  those  usually  given  in  small 
details,  and  is  obtained  from  a  study  of  the  paralysis 
resulting  from  the  section  of  individual  anterior 
primary  divisions  and  the  result  of  experimental 
excitation  during  the  course  of  operative  procedures. 

Fifth  cervical. — Deltoid,  biceps,  brachialis  anticus, 
supinators,  rhomboids,  usually  the  spinati,  occasion- 
ally the  radial  extensors  of  the  wrist,  rarely  the 
j)ronator  radii  teres. 

Sixth  cervical  nerve. — Pronators,  radial  extensors 
of  the  wrist,  clavicular  portion  of  pectoralis  majoi-, 
serratus  magnus. 

Seventh  cervical. — Triceps,  extensor  carpi  ulnaris, 
extensors  of  fingers,  pectoralis  major. 

Eighth  cervical  nerve. — Flexors  of  wrist,  flexors  of 
fingers. 

First  dorsal  nerve. — Intrinsic  muscles  of  hand. , 

Classification. — Lesions    of     the    plexus    may    be 


CAUSATION    OF    PLEXUS    INJURIES   187 

classified  into  supra-  and  infra-clavicular  varieties. 
This  is  important^  for  the  causation  and  prognosis  of 
these  forms  differ  in  most  instances. 

Causation. — Supra-clavicular  injuries  result  usually 
from  indirect  violence,  the  force  being  applied  to  the 
head  or  the  shoulder  ;  infra-clavicular,  usually  from 
the  direct  violence  of  the  dislocated  head  of  the 
humerus. 

Taking  first  the  supra-clavicular  injuries.  In 
addition  to  those  due  to  indirect  violence  they  may 
arise  occasionally  from  the  presence  of  a  cervical 
rib,  complicating  a  fracture  of  the  clavicle,  or  as  the 
result  of  a  penetrating  wound  or  a  fracture  of 
cervical  spine. 

8upra-clavicular  ivjurie!^  due  to  indirect  violence. 
— The  injuries  resulting  from  violence  applied  to 
the  head  or  shoulder  are  due  to  overstretching  of  the 
anterior  primary  divisions  of  the  cervical  nerves  ; 
only  in  rare  cases  are  the  ^^  roots  '^  affected.  They 
fall  into  the  class  of  traction  injuries ;  they  are  not 
due  to  the  direct  pressure  of  the  clavicle  as  has  been 
suggested  by  many  authors.  The  traction  falls  first 
upon  the  upper  part  of  the  fifth  anterior  primary 
division,  then  upon  its  jiinctiuii  with  six,  following 
this  upon  the  I'emaining  divisions  in  order  from 
above  downwards.  The  slight  amount  of  pressure 
necessary  to  produce  overstretching  of  the  plexus  in 
a  child  can  easily  be  seen  by  depressing  tlie 
shoulder;  the  cords  at  once  stand  out  prominently. 


188  •      INJURIES    OF    NERVES 

Injuries  of  this  type,  both  in  children  and  in 
adults,  affect  usually  the  fifth  or  fifth  and  sixth 
anterior  primar}^  divisions  and  produce  the  Erb- 
Duchenne  type  of  paralysis.  There  is  no  reason 
why  the  injuries  sustained  at  birth  should  be 
separated  from  those  of  adult  life,  both  occur  as  the 
result  of  similar  violence,  the  same  muscles  are 
affected  and  the  treatment  identical.  If  the  traction 
fall  upon  the  plexus  from  below — for  example,  a  man 
in  falling  from  a  height  endeavours  to  save  himself 
by  clutching  at  some  projection — the  injury  affects 
the  first  dorsal,  then  the  others  in  order  from  below 
upwards.  The  same  may  result  in  infants  in  breech 
presentations,  with  the  arms  extended,  or  in  certain 
face  presentations. 

In  both  cases  recovery  takes  places  from  the  root 
last  affected,  and  may  leave  an  Erb-Duchenne  or 
Klumpke  paralysis  as  a  terminal  lesion  when  the 
original  affection  was  more  widespread. 

The  actual  method  of  production  of  these  injuries 
has  been  much  discussed  and  many  fanciful  ex- 
planations brought  forward,  such  as  the  compression 
of  the  trunks  between  the  clavicle  and  first  rib,  or 
transverse  processes  of  cervical  vertebrae.  But  it 
was  shown  by  Horsley  as  the  result  of  experiment  in 
1884 — although  this  seems  to  have  been  overlooked  by 
most  writers  on  the  subject — and  later  maintained  by 
Duval  and  Guillain,  and  demonstrated  in  infants  by 
Taylor,  that  the    correct   cause   is  tractinu.      It  has 


TRACTION    INJURIES  189 

been  sliown^  firsi  Ijy  Horsluy^  tliat  the  iiiimt'diiilL' 
lesion  consists  in  a  tearing  of  the  nerve  sheatli,  witli 
liBemorrliage ;  in  more  isevere  cases  a  complete  or 
partial  severance  of  nerve-fibres  may  occur  and  the 
fibres  give  way  at  different  levels.  In  healing,  an 
excess  of  fibrous  tissue  is  formed  which  prevents 
regeneration  in  many  cases. 

Po8t-anxdhnt'ic  parahj>iLt;. — Under  the  term  "  post- 
ani\:stlietic  ^'  or  "  ^^^-^^^"ii'^i'^'^^^c  paralysis/^  many 
nerve  injuries  of  the  upper  limb  liaA'e  been  included. 
Most  are  of  the  Erb-Duchenne  type  and  so  obviously 
supra-clavicular  in  origin  ;  others  from  their  distri- 
bution are  undoubtedly  infra-clavicular ;  in  a  few 
direct  pressure  has  fallen  upon  individual  nerves, 
such  as  the  musculo-spiral.  With  this  last  group 
we  are  not  at  present  concerned. 

These  injuries  are  by  no  means  uncommon, 
although  published  cases  are  few.  Cotton  and  Allen, 
writing  on  the  subject  in  1 903,  were  only  able  to 
collect  thirty  cases. 

Many  causes  have  been  assigned  to  the  production 
of  these  injuries,  but  all  are  agreed  that  the  paralysis 
occurs  only  in  patients  in  whom,  during  the  course  of 
the  operation,  the  arms  are  abducted  and  externally 
rotated  or  raised  above  the  head.  In  my  experience 
they  have  originated  most  often  on  the  right  side  in 
cases  in  which  the  patient  has  been  brought  to  the 
right  side  of  the  operating  table.  The  weight  of 
the   abducted    and    unsupported    arm    causes    over- 


190  INJURIES    OF    NERVES      ^ 

stretcliing'  of  tlie  plexus.  Tliese  cases  are  thus 
brought  into  line  with  the  other  injuries  of  the 
plexus  due  to  indirect  violence.  Stretching  over 
the  head  of  the  humerus  with  the  arms  elevated  is 
the  probable  cause  of  those  injuries  which  are  infra- 
clavicular. 

The  violence  producing  the  injury  is  slight^  the 
division  incomplete  and  the  prognosis  good.  All 
the  cases  that  have  come  under  my  notice  have 
recovered  without  operative  intervention^  and  in  all 
the  recorded  instances  recovery  ensued^  except  in 
one  patient,  in  whom  the  deltoid  muscle  remained 
permanently  paralysed. 

Injuries  associated  icith  the  presence  of  a  cervical 
rih. — The  next  most  common  cause  of  a  supra- 
clavicular lesion  of  the  plexus,  but  falling  far  below 
those  just  mentioned  in  order  of  frequency,  is  that 
due  to  the  presence  of  a  cervical  rib  or  exostosis. 
Unlike  those  we  have  just  been  considering,  it 
affects  fibres  from  the  lowest  roots  entering  into  the 
plexus,  and  is  the  result  of  direct  injury. 

Considerable  interest  has  lately  been  aroused  on  the 
subject.  In  this  country  Thorburn  and  Lewis  Jones 
have  directed  attention  to  it,  and  more  recently  an 
elaborate  paper  has  been  published  in  America  by 
Keen,  analysing  all  the  recorded  cases. 

Briefly,  the  points  are  as  follows  :  The  abnor- 
mality is  more  common  in  Avomen  than  men  and  is 
usually  bilateral,   although   the   symptoms   produced 


V 


CERVICAL    RIBS.  191 

arc,  as  a  rule,  uii  one  side  uiilv — tJic  riirlit.  It  lias 
been  estimated  that  not  more  than  from  5  to  10 
per  cent,  of  those  with  cerv^ical  ribs  present  symptoms, 
and  that  in  abont  two  thirds  of  these  they  are  of  a 
nervous  nature.  As  a  rule  symptoms  do  not  appear 
until  early  adult  life,  resembling  in  this  way  the  late 
involvement  of  the  ulnar  nerve  after  injuries  in  the 
region  of  the  elbow  in  early  life. 

There  may  be  a  general  weakness  of  the  whole 
limb  noticed  at  the  end  of  the  day  or  after  severe 
exertion,  accompanied  by  muscular  wasting,  or,  w^iat 
is  more  usual,  pain  shooting  down  the  inner  side  of 
the  arm  and  forearm  into  the  ulnar  portion  of  the 
hand,  described  by  the  patient  as  neuralgic ;  this  is 
sometimes  accompanied  by  alterations  in  sensibility, 
which  are  rarely  of  a  greater  degree  than  loss  of 
epicritic  sensibility.  Wasting  and  paresis  of  the 
intrinsic  muscles  of  the  hand  is  usually  present;  first 
noticed  and  most  marked  in  those  of  the  thenar 
eminence.  The  lesion  affects  the  inner  cord  of  the 
plexus  formed  of  fibres  from  the  eighth  cer\ical 
and  hrst  dorsal  nerves ;  hence  there  is  no  inter- 
ference with  the  cervical  symi)atlietic,  and  tlie  llexor 
muscles  of  the  hngers  have  been  ah'ected  in  a  few 
instances. 

This  lesion  should  always  be  kept  in  mind  in 
cases  of  brachial  '^  neuralgia '^  and  in  wasting  of  the 
intrinsic  muscles  of  the  hand,  for  many  errors  in 
diagnosis  have  been  made. 


192  IXJUKIES    OF    XER^^ES 

The  treatment  of  tlie  condition  is  simple  and  in 
most  cases  satisfactory — removal  of  the  rib.  It 
rarely  happens  that  the  nerves  themselves  have  to  be 
dealt  with.  After  removal  of  the  cause  the  usual 
after-treatment  should  be  carried  out. 

Complicating  fractures  of  the  clavicle. — As  a  com- 
plication of  a  fracture  of  the  clavicle^  brachial  plexus 
injury  is  uncommon.  Taylor^  in  1903_,  was  only  able 
to  collect  ten  cases^  and  I  have  had  one  patient  with 
this  complication  under  my  care.  In  most,  including 
the  one  I  have  recorded,  the  nerve  injury  was  due  to 
the  violence  producing  the  fracture  and  not  to 
pressure  on,  or  laceration  of,  the  nerves  by  the  ends 
of  the  bone.  In  some  instances  the  fracture  was 
due  to  direct  violence,  often  from  gunshot  wounds, 
in  others,  including  the  case  I  have  recorded,  to 
indirect  violence  applied  to  the  point  of  the  shoulder, 
causing  a  fracture  of  the  clavicle  at  the  junction  of 
its  outer  and  middle  thirds  and  a  traction  injury  of 
the  plexus. 

Penetrating  wounds.  —  Penetrating  wounds  in- 
volving the  plexus  are  rare.  I  have  reported  one 
such  case,  in  which  the  fifth  anterior  primary 
division  was  divided  together  Avith  the  descending 
branches  of  the  cervical  plexus,  producing  a  t^q^ical 
Erb-Duchenne  paralysis  with  loss  of  sensibility  over 
the  point  of  the  shoulder. 

In  military  practice  injuries  of  the  plexus,  due  to 
gunshot  wounds,  have  been  by  no  means  uncommon. 


SYMPTOMS    OF    PLEXUS    INJURIES    193 

Infra-clavicular  injuries  of  the 'plexus. — In  its  infra- 
clavicular course^  i^^j^^y  most  often  results  from  the 
direct  pressure  of  the  dislocated  head  of  the  humerus, 
occasionally  from  attempts  made  to  reduce  it  by  the 
heel-in-axilla  method,  sometimes  from  fracture  of  the 
upper  end  of  the  humerus  or  of  the  neck  of  the  scapula. 

The  whole  plexus  may  suifer,  but  more  often  the 
inner  cord  alone,  rarely  the  outer.  In  unreduced 
dislocations  of  the  humerus,  pain  and  tenderness  may 
result  from  changes  in  the  nerves,  due  to  pressure, 
and  may  indicate  operation  ;  in  other  cases  paralysis 
may  supervene  from  the  same  cause.  In  attempts  at 
reduction  either  by  manipulation  or  open  operation, 
plexus  injuries  have  been  produced. 

Symptoms  produced  by  injuries  of  the  plexus. — There 
are  three  well-known  types  of  brachial  plexus  lesion 
due  to  supra-clavicular  injuries  and  produced  by 
indirect  violence  :  the  whole  plexus,  the  upper  arm 
type  (Erb-Duchenne)  and  the  lower  arm  type 
(Klumpke).  As  a  permanent  affection  the  upper 
arm  type  is  the  most  common  ;  more  than  60  per 
cent,  of  the  patients  present  this  form  of  paralysis 
when  seen  by  the  surgeon.  In  many  instances  the 
symptoms  noticed  immediately  after  the  accident 
diminish  in  extent ;  the  initial  distribution  may  be 
the  whole  plexus,  some  recovery  ensues  and  the  con- 
dition remains  stationary  as  an  upper  arm  type  of 
lesion.  In  other  cases  muscles  supplied  by  other  roots 
are  also  affected  ;  these,  it  is  impossible  to  classify. 

13 


194  INJURIES    OF    NERVES 

In  infra-clavicular  lesions  the  inner  cord  and  the 
whole  plexus  are  the  only  common  types.  Here  a 
lesion  of  the  whole  plexus  often  becomes  later^  one 
of  the  inner  cord  only. 

The  whole  plexus. — This  results  usually  from  in- 
direct violence  applied  to  the  head  or  shoulder^ 
rarely  as  the  result  of  a  dislocation  of  the  humerus, 
or  from  attempts  made  to  reduce  it.  It  is  a  some- 
what uncommon  accident,  for  Bristow,  in  1902,  was 
only  able  to  collect  twenty-four  instances  of  lesion  of 
the  whole  j)lexus  due  to  indirect  violence.  I  have 
had  three  cases  under  observation. 

The  symptoms  produced  by  division  of  the  whole 
plexus  will  depend  to  a  certain  extent  upon  the 
level  of  the  injury,  whether  supra-  or  infra- clavicular, 
roots,  primary  divisions  or  cords.  In  a  supra- 
clavicular division  the  loss  of  sensibility  is  the  same 
whatever  the  level  of  the  lesion. 

Epicritic  and  protopathic  sensibility  are  lost  over 
the  whole  of  the  forearm  and  hand  and  over  the  outer 
surface  of  the  arm  in  its  lower  two  thirds,  the  area 
overlapping  on  to  the  anterior  and  posterior  surfaces 
{vide  Plates  VIII  and  IX).  The  sensitive  area  on 
the  point  of  the  shoulder  gives  the  full  supply  of  the 
descending  branches  of  the  cervical  plexus,  that  on  the 
inner  side  of  the  arm  the  portion  of  skin  supplied  by 
the  intercos  to-humeral  and  small  internal  cutaneous 
nerves.      Deep  touch  is  lost  over  the  forearm. 

In  lesions  of  this  type  the   sympathetic  is  usually 


PLATE   YIII. 


From  a  patient  with  complete  division  of  the  Ijrachial  plexus 
in  the  supra-clavicvilar  region.  To  show  the  boundaries  of 
the  loss  of  epicritic  and  protopathic  sensibility. 


To  face  p.  194. 


Adlard  4'  Son,  Impr. 


PLATE   TX. 


From  the  same  patient  as  Plate  VIII. 


To  face  p.  195. 


Adhtrd  .f-  Son,  Impr. 


INJURIES   OF  THE   WHOLE  PLEXUS     195 

alfected  and  all  tlie  symptoms  indicative  of  a  lesion 
of  the  cervical  sympathetic  present^  but  the  pupil, 
although  it  does  not  dilate  to  shade,  usually  dilates 
to  cocaine,  so  that  the  involvement  is  incomplete. 

If  the  lesion  is  infra-clavicular  the  sensitive  strip 
on  the  inner  side  of  the  arm  may  be  absent  if,  as  is 
so  often  the  case,  the  injury  has  been  caused  by 
direct  pressure,  such  as  the  heel  in  the  axilla  during 
the  reduction  of  dislocations. 

Li  all  cases  of  complete  loss  of  conduction  in  the 
plexus  all  the  muscles  of  the  arm,  forearm  and  hand 
are  paralysed.  The  level  of  the  lesion  will  determine 
whether  the  spinati,  rhomboids,  serratus  magnus  and 
pectorals  are  paralysed  or  the  sympathetic  involved. 
Li  the  usual  type  of  complete  plexus  injury  due  to 
indirect  violence  the  pectorals  and  spinati  are 
paralysed  and  the  sympathetic  involved,  but  the 
rhomboids  and  serratus  magnus  escape. 

Erh-Duclienne  paralysis.  —  When  the  result  of 
injury,  this  form  of  paralysis  is  usually  due  to  indirect 
violence,  very  rarely  to  a  penetrating  wound  or  the 
pressure  of  a  tumour.  It  was  at  one  time  considered 
to  be  due  to  interference  with  conduction  in  the 
anterior  primary  division  of  the  sixth  as  well  as  the 
fifth  cervical  nerves,  but  it  is  certain  that  section  of 
the  fifth  anterior  primary  division  alone  can  produce 
it.  Wilfred  Harris,  as  the  result  of  his  dissections 
and  of  his  clinical  observations  with  Warren  Low, 
came  to  this  conclusion.      I  have  been  able  to  confirm 


196  IXJUEIES    OF    NEEYES 

this,  both  as  the  result  of  operatiye  findings  in 
cases  of  this  form  of  paralysis,  and  by  stimulation 
of  this  division  during  the  course  of  operations.  In 
some  instances  both  five  and  six  may  be  involved; 
the  involvement  of  six  at  its  junction  vdth  five 
has,  in  my  experience,  no  further  effect,  at  most 
paralysis  of  the  clavicular  portion  of  the  pectoralis 
major  may  result ;  the  branches  given  by  this  nerve 
to  the  serratus  mao-nns  are  o-iven  off  above  the  level 
of  the  lesion.  In  patients  in  whom  the  junction  of 
five  and  six  have  been  excised  no  further  paralysis 
resulted  than  that  already  due  to  the  injury  of  the 
fifth  nerve.  In  several  cases  in  which  I  performed 
nerve  anastomosis  in  this  region  I  was  able  to  stimu- 
late six  with  the  interrupted  current ;  this  produced 
a  contraction  of  the  clavicular  portion  of  joectoralis 
major,  and  in  one  a  feeble  resjoonse  in  the  triceps. 
It  seems  jDrobable,  therefore,  that  the  sixth  cervical 
nerve  supplies  no  group  of  muscles  in  the  arm  and 
forearm  in  a  manner  similar  to  the  supply  of  the 
deltoid,  biceps,  brachialis  anticus  and  supinators  from 
the  fifth.  The  main  supply  of  the  triceps  appears 
to  come  from  the  seventh ;  this  agrees  with  the 
anatomical  researches  of  Herringham. 

The  position  of  the  upper  limb  in  patients  with 
this  form  of  paralysis  is  typical.  The  arm  and  fore- 
arm hang  close  to  the  side,  with  the  forearm 
extended  and  pronated.  There  is  obvious  wasting 
in  late  cases,  of  the  deltoid  and  flexors  of  the  fore- 


BRB-DUCHENNE    PARALYSIS  197 

arm.  The  deltoid,  spinati,  biceps,  bracliialis  anticus 
and  supinators  are  paralysed.  It  was  pointed  out 
by  Harris  and  Low  that  the  radial  extensors  of  the 
wrist  and  the  pronator  radii  teres  might  be  affected. 
In  a  patient  upon  whom  I  operated  and  found  the 
fifth  anterior  primary  division  torn  tlirough,  the 
radial  extensors  of  the  wrist  were  paralysed ;  this  is 
the  only  case  in  which  I  have  observed  paralysis  of 
these  muscles  from  this  cause,  but  in  one  patient 
with  a  lesion  of  the  lower  divisions  they  escaped 
together  with  the  muscles  usually  supplied  by  the 
fifth.  So  far  I  have  been  unable  to  observe  any 
affection  of  the  pronator  radii  teres. 

A  patient  with  this  paralysis  is  unable  to  supinate 
the  forearm  and  to  abduct  the  arm,  and  in  most 
cases  to  flex  the  forearm.  But  he  may  regain  some 
power  of  flexion  of  the  forearm  or  possess  this  move- 
ment on  coming  under  observation,  although  no 
recovery  has  taken  place  in  the  paralysed  muscles. 
Flexion  of  the  fully  pronated  forearm  may  be 
carried  out  by  tlie  muscles  arising  from  the  external 
condyle  of  the  humerus,  the  extensors  of  the  wrist 
becoming  feeble  flexors  of  the  forearm. 

There  is,  as  a  rule,  no  loss  of  sensibility  accom- 
panying this  form  of  paralysis.  This  was  first 
recorded  by  Duchenne  and  has  been  confirmed  by 
all  subsequent  observers.  Even  when  the  fifth  and 
sixth  anterior  primary  divisions  are  divided  together 
there  may  be  no  obvious  change,  but  there  is  usually 


198  INJURIES    OF    NERYES 

some  diminution  or  loss  of  epicritic  sensibility  on  the 
outer  surface  of  the  arm  and  forearm.  But  although 
there  is  no  loss  of  sensibility  after  division  of  the 
fifth^  it  is  not  uncommon  to  have  complaint  made  of 
peculiar  feelings^  ticklings  pins  and  needles^  over  the 
outer  side  of  the  arm.  In  several  of  these  cases 
careful  examination  has  revealed  no  objective  change^ 
the  compass  test  was  normally  appreciated^  and  minor 
degrees  of  temperature  accurately  discriminated. 

After  this_,  as  after  other  nerve  injuries^  the 
abnormal  position  of  the  limb  may  persist  although 
the  muscles  have  regained  their  power  of  voluntary 
movement^  and  these  may  remain  ]3ermanently  Avasted 
although  they  react  to  stimulation  with  the  inter- 
rupted current.  Such  cases  have  led  to  errors  in 
diagnosis  and  probably  to  unnecessary  treatment. 
Patients  have  come  under  my  observation  as  examples 
of  nerve  injury  suitable  for  operation^  in  whom 
examination  revealed  the  fact  that  recovery  had 
taken  place^  but  the  abnormal  position  of  the  limb 
had  remained  because  of  the  lack  or  inefficiency  of 
the  after-treatment.  In  these  cases  the  diagnosis  of 
an  old  injury  to  the  fifth  cervical  nerve  is  obvious^ 
yet  all  the  muscles  are  acting  and  react  normally. 

The  injury  to  the  fifth  anterior  primary  division 
may  be  incomplete^,  and  this  incomplete  division  may 
be  anatomical  or  physiological ;  it  is  very  necessary 
to  bear  this  in  mind.  Over-stretching  of  the  fifth 
nerve  may  produce  a  haemorrhage  in  its  sheath,  with 


PARALYSIS    OF    DELTOID.  199 

compression  of  the  whole  nerve,  or,  on  the  other 
hand,  a  rnjDture  of  some  of  its  fibres.  In  the  former 
case  there  is  paralysis  of  all  the  muscles  supplied  by 
the  nerve  with  the  typical  reactions  of  incomplete 
division ;  in  the  latter  the  fibres  in  the  upper  part  of 
the  nerve  supplying  the  deltoid  and  spinati  suffer, 
leading  to  paralysis  of  these  muscles,  without 
affecting  the  flexors  of  the  forearm  and  the  sujDi- 
nators.  The  reaction  of  degeneration  may  develop  in 
the  spinati  and  deltoid  without  the  biceps  and 
supinator  muscles  being  in  any  way  affected,  or  after 
an  Erb-Duchenne  paralysis  the  spinati  and  deltoid 
may  be  left  as  a  permanent  paralysis,  the  other 
muscles  having  recovered.  I  have  described  cases  of 
tliis  nature,  upon  one  of  whom  I  operated,  and  was 
able  to  demonstrate  the  lesion  in  the  upper  part  of 
five,  and  by  stimulation  with  the  interrupted  current 
to  obtain  contraction  in  the  flexors  and  supinators, 
while  the  deltoid  remained  flaccid.  As  this  form 
of  paralysis  follows  a  fall  on  the  shoulder  great  care 
is  necessary  in  diagnosis  ;  these  are  the  cases  that 
are  usually  described  as  caused  by  an  injury  to  the 
circumflex  from  a  blow  on  the  shoulder. 

Loicer  arm  tyi^e  of  j^ciralysis. — This  type,  usually 
called  after  Klumpke,  who  described  it  fully,  was 
first  mentioned  by  Flaubert  in  1827.  It  may  arise 
from  overstretching  of  the  plexus,  as  the  result  of 
penetrating  wounds,  sometimes  from  involvement  in 
growth.      When  resulting  from  traction  the  violence 


200  INJURIES    OF    NEEYES 

affects  tlie  roots  from  below,  as  in  falling  from  a 
heiglit  and  grasping  at  a  projection_,  or  from  over- 
flexion  or  over-extension  of  the  neck  ;  in  these  last 
cases  it  may  be  bilateral. 

In  a  typical  example  of  this  paralysis  all  the 
intrinsic  muscles  of  the  hand  are  affected  and  the 
hand  assumes  the  true  claw  shape.  Sensibility  is 
usually  altered  over  the  inner  side  of  the  arm  and 
forearm,  sometimes  also  on  the  ulnar  border  of  the 
hand,  the  loss  of  sensibility  to  prick  being  in  most 
cases  larger  than  that  to  light  touch.  In  some,  the 
lono'  flexors  of  the  fino-ers  suffer  in  addition,  but  it  is 
probable  that  in  these  instances  the  eighth  cervical 
is  also  injured,  but  lesions  of  this  nature  verified 
by  operation  are  few,  and  further  study  is  necessary 
before  coming  to  any  definite  conclusion. 

Characteristic  orbital  symptoms  are  present,  due 
to  involvement  of  the  branches  given  from  this  nerve 
to  the  cervical  sj^'mpathetic. 

T}ie  inner  cord. — Injury  to  this  cord  is  the  most 
common  lesion  of  the  ^^lexus  after  an  Erb-Duchenne 
paralysis.  It  is  most  often  produced  by  a  sub- 
coracoid  dislocation  of  the  humerus,  and  is  rarely 
complete. 

The  muscles  paralysed  are  those  supplied  by  the 
ulnar  nerve  with,  in  addition,  those  intrinsic  muscles 
of  the  hand  supplied  by  the  median,  i.  e.  all  the 
intrinsic  muscles  of  the  hand  suffer. 

Sensibility  is  affected  over  the  inner    (post   axial) 


CORDS    OF    THE    PLEXUS  201 

surface  of  the  forearm  and  ulnar  area  of  the  hand. 
Usually  the  loss  is  of  epicritic  sensibility  only^ 
but  when  the  division  is  complete  both  forms  are 
affected. 

Outer  cord. — This  may  be  injured  in  dislocations 
of  the  humerus^  but  it  is  unusual. 

Its  division  results  in  paralysis  of  the  biceps^ 
coraco-brachialis  and  all  the  muscles  supplied  by  the 
median^  except  the  intrinsic  muscles  of  the  hand. 
It  is  easy  to  overlook  this  injury  unless  the  action  of 
the  individual  muscles  is  studied_,  for^  as  in  a  patient 
that  was  under  my  care^  the  forearm  may  be  flexed 
by  the  supinator  longus  and  supinated  by  the 
supinator  brevis^  and  the  paralysis  of  the  long- 
muscles  of  the  fingers  is  often  not  discovered  (xide 
median  nerve_,  p.  267). 

Sensation  is  affected  on  the  outer  (pre-axial) 
surface  of  the  forearm  to  a  degree  varying  with  the 
injury.  Its  anterior  boundary  is  well  defined,  the 
posterior  ill  defined  and  fading  away  into  the 
normal  sensibility  of  the  area  supplied  in  common 
with  the  descending  branch  of  the  musculo-spiral. 

Posterior  cord. — No  difficulty  should  arise  in  the 
recognition  of  this  rare  form  of  injury.  The 
paralysis  of  the  muscles  supplied  by  the  musculo- 
spiral  and  circumflex  nerves  and  the  alteration  in 
sensibility  over  the  areas  of  skin  supplied  by  them 
is  typical.  It  results  most  often  from  a  dislocation 
of  the  humerus. 


202  INJURIES    OF    NEEVBS 

Treatment  of  brachial  plexus  injuries. — Treatment  is 
carried  out  along  tlie  lines  already  laid  down.  As 
most  are  subcutaneous  injuries  it  is  impossible  to 
make  the  diagnosis  of  complete  or  incomplete  division 
until  sufficient  time  has  elapsed  to  allow  of  the 
establishment  of  the  reaction  of  degeneration.  If 
at  the  end  of  fourteen  days  this  is  present^  operation 
should  not  be  delayed. 

In  supra-clavicular  lesions  of  the  whole  plexus^ 
good  exposure  is  given  through  an  incision  starting 
at  the  posterior  border  of  the  sterno-mastoid  muscle 
at  the  junction  of  its  upper  and  middle  thirds^  and 
carried  downwards  and  outwards  to  the  junction  of 
the  outer  and  middle  thirds  of  the  clavicle ;  in  some 
cases  it  will  be  necessary  temporarily  to  divide  this 
bone.  When  operation  is  delayed  it  is  usually  im- 
possible to  identify  the  individual  nerves  in  the  mass 
of  fibrous  tissue  with  which  they  are  incorporated^ 
and  to  bring  ends  which  have  been  identified^  into 
apposition  after  its  removal.  Patient  and  careful  dis- 
section may  bring  the  upper  ends  into  view  ;  it  may  be 
impossible  to  identify  the  individual  lower  ends^  and 
in  many  cases  they  have  had  to  be  sutured  without 
exact  knowledge.  It  is  only  when  these  cases  are 
operated  upon  early  that  complete  success  is  likely  to 
ensue.  No  instance  of  perfect  recovery  after  secondary 
suture  of  the  whole  plexus  has  been  recorded. 

The  anterior  primary  divisions  of  five  and  six  may 
be   easily    exposed   through   a    similar   incision.      In 


TREATMENT   OF   PLEXUS  INJURIES    203 

deepening  tliis  it  is  important  to  avoid  injury  to  the 
descending  brandies  of  the  cervical  nerves.  The 
posterior  border  of  the  sterno-mastoid  is  freed  and 
drawn  inwards  and  the  nerves  sought  as  they  pass 
out  from  under  cover  of  the  scalenus  anticus.  The 
junction  of  five  and  six  is  brought  into  view  after  a 
little  dissection_,  with  the  upper  trunk  formed  by 
their  junction  and  its  division  into  three  branches, 
the  supra-scapular  and  the  branches  to  the  outer 
and  posterior  cords.  Tracing  the  nerves  up  from 
their  junction  the  seat  of  the  injury  is  easily  found. 
The  supra-scapular  nerve  should  always  be  examined  ; 
I  have  found  it  divided  in  addition  to  the  fifth 
cervical.  The  phrenic  nerve  exposed  on  the  anterior 
surface  of  the  scalenus  anticus  must  be  avoided.  In 
the  cases  in  which  the  deltoid  and  spinati  alone  are 
paralysed  and  give  the  reaction  of  degeneration,  the 
damaged  portion  may  be  excised  and  a  portion  of 
the  radial  nerve  inserted,  or  these  upper  affected 
fibres  may  be  anastomosed  to  the  sixth  anterior 
primary  division. 

In  the  typical  lower  arm  type  of  paralysis  the 
lesion  is  situated  in  the  first  dorsal  anterior  primary 
division,  too  high  to  admit  of  direct  union.  Tem- 
porary division  of  the  clavicle  is  necessary  to  expose 
it,  and  anastomosis  to  the  eighth  cervical  anterior 
primary  division  Avill  be  necessary  in  most  cases. 

In  all  cases  of  incomplete  division  and  after 
suture    the    usual   after-ti-eatment  must  be   persisted 


204  INJURIES    OF    NERVES 

in  until  recovery  ensues^  and  care  must  be  taken  to 
see  that  the  paralysed  muscles  do  not  become  over- 
stretched. 

Prognosis  of  brachial  plexus  injuries. — There  are  a 
few  points  that  have  to  be  considered  in  regard  to 
the  prognosis  of  these  lesions.  The  majority  of 
the  injuries  are  subcutaneous^  and  there  is  no 
doubt  that  these  have  a  much  worse  prognosis  than 
subcutaneous  injuries  of  peripheral  nerves  else- 
where^ due  chiefly  to  differences  in  causation.  In 
an  important  paper  on  the  plexus^  published  by 
Warrington  and  Jones^  ^'^'^^J  came  to  the  conclusion^ 
from  the  examination  of  cases  under  their  care^  that 
spontaneous  recovery  took  place  only  in  about  30  to 
40  per  cent,  of  the  cases.  BrQns_,  in  a  paper  which 
has  been  widely  quoted_,  came  to  a  similar  conclusion ; 
he  found  that  of  cases  of  injury  to  peripheral  nerves 
(excluding  complete  section  and  suture) _,  treated 
without  operation^  66  per  cent,  recovered ;  of  plexus 
injuries_,  26  per  cent.  only.  But  on  looking  through 
the  cases  on  which  he  has  based  his  figures  it  is  at 
once  obvious  how  different  is  their  causation  in  the 
two  groups.  It  is  impossible  to  compare  in  this 
way,  for  example,  a  case  of  paralysis  of  the  musculo- 
spiral  due  to  a  fractured  humerus,  or  pressure  during 
sleep,  with  an  Erb^s  paralysis  due  to  overstretching 
of  the  plexus.  In  discussing  the  reason  for  this 
relatively  bad  prognosis  he  seems  to  have  lost  sight 
of  this  difference  in  causation,  and  considered  that  in 


PROGNOSIS    OF    PLEXUS    INJURIES   205 

many  instances  there  was  an  injury  to  anterior  horn 
cells.  But  there  is  no  evidence  that  this  is  of 
common  occurrence  in  brachial  plexus  injuries. 

In  considering  the  prognosis  we  have  to  take  into 
account  the  cause  of  the  symptoms,  and  to  separate, 
for  this  reason,  examples  of  injury  above  the  clavicle 
from  those  below.  The  prognosis  has  to  do  first — 
and  this  applies  to  supra-  and  infra-clavicular 
injuries — with  the  distance  of  the  injury  from  the 
periphery.  To  take  a  simple  illustration,  division  or 
injury  of  the  ulnar  nerve  at  the  elbow  is  of  more 
serious  import  than  when  the  injury  takes  place  at 
the  wrist,  in  the  axilla  than  at  the  elboAv ;  longer 
time  is  necessary  before  recovery  ensues,  con- 
sequently the  greater  the  chance  of  permanent 
damage. 

But  the  nature  of  the  injury  bears  still  more 
on  the  question.  Situation  has  to  do  with  time ; 
causation  may  abolish  altogether  the  possibility  of 
spontaneous  recovery.  Years  must  elapse  in  a  case 
of  suture  of  the  brachial  plexus  before  the  muscles 
can  again  be  innervated,  and  unless  the  treatment  in 
the  interval  has  been  kept  up^  the  nerves  find  fibrotic 
and  contracted  muscles  to  act  upon.  Traction  in- 
juries make  up  a  large  proportion  of  plexus  injuries, 
and  it  is  easy  to  understand  how  little  tendency 
there  is  in  the  more  severe  cases  for  spontaneous 
recovery  to  take  place.  A  complicated  scar  is  pro- 
duced   in   which   nerve-fibres  have   been  divided  at 


206  INJURIES    OF    NERVES 

different  levels^  lience  any  recovery  that  takes  place 
is  frequently  imperfect. 

The  prognosis  in  infra-clavicular  lesions  is  much 
brighter.  These  injuries^  which  result  in  most  cases 
from  dislocation  of  the  humerus^  in  my  experience 
invariably  recover  without  surgical  intervention, 
although  of  the  cases  recorded  by  Bruns  five  out  of 
six  did  not  recover  power,  but  the  only  case  reported 
by  Warrington  and  Jones  made  an  excellent 
recovery. 

Brachial  birth  paralysis. — Although,  as  already 
pointed  out,  these  lesions  differ  in  no  respect  from 
similar  nerve  injuries  in  the  adult,  yet  it  w411  be 
convenient  to  discuss  them  a^Dart. 

Our  present  knowledge  of  the  subject  dates  from 
1872,  when  Duchenne  described  four  infants  who  at 
birth  presented  what  we  noAv  call  Erb-Duchenne 
paralysis,  without  any  alteration  in  sensibility.  But 
these  were  by  no  means  the  first  examples  of 
paralysis  of  the  arm  described  in  newborn  infants. 
Smellie,  as  early  as  1768,  mentioned  its  occurrence. 

It  has  been  demonstrated  beyond  doubt  that  the 
lesion  is,  as  originally  described  by  Duchenne,  due  to 
traction.  The  operative  findings  and  the  micro- 
scopical examination  of  portions  of  nerve  removed  by 
Clark,  Taylor  and  Prout,  and  the  post-mortem 
examinations  recorded  by  Schmidt  and  others  have 
settled  the  question.  In  all  severe  cases  the  cause 
of  the  paralysis  is  over-stretching  of  the  plexus ;  in 


BRACHIAL    BIRTH    PARALYSIS        207 

some  of  the  less  severe  cases  the  direct  pressure  of 
the  accoucheur's  fingers  may  be  the  cause. 

The  lesion  is  produced  with  almost  equal  frequency 
in  breech  and  in  vertex  presentations.  Thus^  in 
ninty-three  cases  collected  by  Schumacher,  fifty 
Avere  vertex,  forty  were  breech.  The  whole  j^lexus 
may  be  affected  or  the  paralysis  may  be  of  the  upj^er 
or  of  the  lower  arm  type.  The  injury  is  usually 
unilateral  and  the  left  arm  is  more  often  affected 
than  the  right.  In  about  80  per  cent,  of  the  cases 
the  lesion  is  of  the  upper  arm  type.  When  the 
whole  plexus  is  at  first  affected  some  spontaneous 
recovery  usually  occurs,  and,  as  a  rule,  a  residual 
upper  arm  paralysis  is  left. 

Paralysis  of  the  lower  arm  type  is  of  great  rarity, 
Stransky  found  it  in  twelve  out  of  ninety-four  cases, 
and  Thomas  was  only  able  to  collect  sixteen  examples, 
but  this  by  no  means  represents  its  true  frequency ; 
it  is  much  rarer  than  this,  for  many  of  the  common 
upper  arm  type  are  not  recorded.  The  lower  arm 
type  occurred  most  often  as  the  result  of  breech 
presentations  with  extended  arms,  a  few  after  face 
presentations.  Batty  Shaw  has  recorded  a  case  in 
which  it  resulted  from  traction  a23plied  to  the  axilla. 
As  a  rule  the  paralysis  is  unilateral,  but  a  few 
cases  of  bilateral  lower  arm  palsy  have  been 
described. 

It  is  not  usual,  at  any  rate  in  hospital  practice, 
to  find   the   lesion   recognised   at   birth.       The   first 


208  INJURIES    OF    NERYES 

symptom  noticed  is  often  tenderness  in  the  supra- 
clavicular region,  the  child  crying  when  this  is 
touched  or  the  arm  moved,  hence  the  diagnosis  of  a 
fracture  of  the  clavicle  or  upper  end  of  the  humerus 
is  not  infrequently  made.  By  carefully  watching 
the  child  the  nature  of  the  lesion  is  discovered. 
The  position  typical  of  an  Erb-Duchenne  paralysis 
is  usually  present ;  in  other  cases  the  whole  of  the 
muscles  of  the  upper  limb  are  flaccid  and  the  arm 
hangs  powerless ;  in  still  a  few  others,  the  arm  is 
abducted,  and  it  is  evident  that  the  injury  has  fallen 
on  the  plexus  from  below. 

But  it  is  impossible  to  tell  the  degree  of  the 
injury  by  inspection  alone,  electrical  examination  of 
the  affected  muscles  is  necessary.  But  in  infants 
this  cannot,  as  a  rule,  be  satisfactorily  carried  out 
before  the  child  is  three  months  old,  when  under  an 
angesthetic  reliable  results  may  be  obtained. 

Diagnosis.— Csbve  must  be  taken  to  avoid  mis- 
taking immobilisation  of  the  limb  from  other  causes, 
such  as  fracture,  for  paralysis,  but  the  fault  usually 
lies  in  the  opposite  direction.  It  is  essential  to 
make  certain  that  the  lesion  is  peripheral  and  not 
due  to  cerebral  injury. 

Prognosis. — There  is  no  doubt  that  a  large  pro- 
portion of  all  cases  of  brachial  birth  paralysis 
undergo  spontaneous  recovery,  but  no  definite 
opinion  can  be  given  in  an  individual  case  until  the 
child  is  old  enough  to  have  the  electrical  reactions 


TREATMENT  OF  BIRTH  PARALYSIS     209 

of  the  affected  muscles  tested.  Those  cases  with 
marked  tenderness  rarely  recover  completely. 

If,  when  the  patient  comes  under  observation,  the 
reaction  of  degeneration  is  present,  complete  recovery 
apart  from  operation  is  unlikely. 

Spontaneous  recovery  has  taken  place  in  about 
70  per  cent,  of  the  cases  that  have  come  under  my 
observation.  In  many  the  paralysis  had  completely 
disappeared  by  the  time  the  child  was  brought  to 
have  its  electrical  reactions  tested  at  the  age  of  three 
months.  Complete  spontaneous  recovery  rarely  takes 
place  if  no  improvement  is  noticed  by  this  date. 

Brunts  figures  are  more  gloomy ;  he  found  26  per 
cent,  only  of  spontaneous  recoveries. 

Trbatment. — These  lesions  are  treated  on  the  same 
lines  as  similar  injuries  of  the  plexus  in  the  adult. 
The  upper  limb  is  kept  at  rest  with  the  affected 
muscles  relaxed,  and  as  soon  as  all  tenderness  has 
ceased  daily  massage  and  passive  movement  em- 
ployed. If  relaxation  of  the  affected  muscles  is  not 
insisted  upon  j^ermanent  deformity  may  result, 
although  the  muscles  regain  their  voluntary  power 
and  electrical  excitability.  The  electrical  reactions 
should  be  tested  under  an  anaesthetic  at  the  end  of 
ten  or  twelve  weeks.  If  the  reaction  of  degeneration 
is  present  operation  should  be  undertaken  as  soon 
as  convenient.  If  the  health  of  the  child  will  not 
permit  of  operation,  delay  of  a  few  months  will 
probably  affect  the  tinal  result  little,  so  long  as   the 


210  INJUEIES    OF    NEEYES 

correct  non-operative  treatment  is  being  carried 
out. 

The  lengtli  of  tlie  incision  necessary  to  expose  tlie 
anterior  primary  divisions  of  the  plextis  will  depend 
upon  the  extent  of  the  injury.  If  the  lower  divisions 
are  involved  it  will  be  necessary  to  divide  the 
clavicle.  In  the  usual  upper  arm  type  the  junction 
of  five  and  six  is  sought.  Often  the  deep  fascia  is 
found  thickened  and  adherent  to  the  injured  nerves. 
The  supra-clavicular  nerve  must  always  be  exposed 
and  examined. 

In  many  cases  the  nerves  are  found  in  anatomical 
continuity^,  but  on  palpating  five  at  its  junction  with 
six  a  scar  is  found  ;  this  must  be  excised  and  end-to- 
end  union  carried  out.  In  some  cases  five  may  be 
found  completely  divided  anatomically ;,  in  others  the 
supra-scapular  nerve  may  be  discovered  torn  through 
in  addition.  If  end-to-end  union  is  impossible^ 
complete  jDcripheral  anastomosis  is  carried  out  to  a 
neighbouring  nerve. 

After  closure  of  the  wound  the  shoulder  must  be 
elevated  so  that  no  tension  falls  on  the  junction^  and 
the  limb  kept  in  this  position  until  the  wound  is 
soundly  healed.  For  complete  success  the  after- 
treatment  must  be  faithfully  carried  out. 


CHAPTER    XIV 

Injuries  to  tlie  Nerves  supplying  the  Muscles  of  the  Shoulder 
Girdle — The  Long  Thoracic  Nerve  :  Winging  of  the  Scapula 
— The  Supra-scapular  Nerve— The  Nerve  to  the  Rhomboids 
— The  Cii'cumflex  Nerve. 

The  long  (posterior)  thoracic  nerve,  nerve  of  Bell. — 
This  nerve,  which  supplies  the  serratus  magnus, 
arises  by  three  roots  from  the  fifth,  sixth  and  seventh 
cervical  nerves,  that  o-iven  from  the  sixth  being-  tlie 
most  important ;  its  upper  two  roots  pass  through 
the  scalenus  medius  muscle,  and  after  uniting  on  its 
anterior  surface  lie  here  for  a  short  distance.  The 
lower  root  does  not  perforate  the  scalenus  medius, 
but  passes  in  front  to  join  the  trunk  opposite  or 
below  the  first  rib.  The  upper  roots  are  thus 
exposed  to  injury  in  the  neck. 

Paralysis  of  the  serratus  magnus,  the  result  of 
injury,  is  seen  most  often  in  males  between  the  ages 
of  twenty-five  and  forty,  commonly  on  the  right 
side.  The  nerve  suffers  in  most  instances  as  the 
result  of  direct  pressure  applied  to  the  supra- 
clavicular region  in  those  whose  occupation  entails 
carrying  weights  on  the  shoulder.  It  has  been  said 
to  be  due  to  compression  of  the  nerve  between  the 


212  INJUBIES    OF    NEEYES 

first  rib  and  coracoid  process  of  the  scapula  ;  this  is 
unlikely. 

Paralysis  of  the  serratus  magnus  is  rare  as  an 
isolated  lesion ;  its  tetiology  explains  the  reason^  due 
in  a  large  proportion  of  the  cases  to  direct  pressure 
above  the  clavicle^  other  nerves  ^^assing  across 
this  region^  the  branches  given  from  the  third  and 
fourth  cervical  to  the  lower  trapezius^  the  nerve  to 
the  rhomboids^  or  the  sensory  branches  of  the 
cervical  plexus^  may  be  injured.  Hence  the  para- 
lysis of  the  lower  trapezius  which  usually  accompanies 
it  and  the  sensory  disturbance. 

Considerable  difference  of  opinion  has  existed 
with  regard  to  this  j^aralysis.  Duchenne  in  twenty 
cases  had  never  seen  an  example  of  isolated 
paralysis^  and  Lewinski^  in  1878_,  reviewing  the 
recorded  cases^  was  only  able  to  find  one  in  which 
other  muscles  were  not  affected.  More  recently^ 
following  Steinhausen^  authors  have  come  to  consider 
an  isolated  lesion  of  this  nerve  more  common.  It  is 
certainly  uncommon  in  England.  The  cases  Avhich 
follow  violence  above  the  clavicle  are  never  isolated^ 
those  due  to  occupation  or  a  sudden  muscular  effort 
may  be.  The  nerve  is  sometimes  severed  during 
operations  upon  the  upper  part  of  the  axilla,  and 
has  been  divided  during  the  complete  operation  for 
carcinoma  of  the  breast. 

The  winged  scapula  commonly  reputed  to  be  due 
to  an  affection  of  the  long  thoracic  nerve  is  in  most 


WINGING-    OF    THE    SCAPULA         213 

cases  a  combined  lesion,  due  to  paralysis  of  the 
serratus  magnus  and  lower  trapezius,  and  the  sym- 
ptoms produced  are  as  follows  :  Pain  is  often  com- 
plained of  radiating  from  the  supra-clavicular 
region.  There  is  a  conspicuous  winging  of  the 
scapula;  on  marking  out  the  spine  and  lower  angle 
of  each  scapula  and  comparing  their  position,  it  is 
seen  that  in  addition  to  the  prominence  of  the  lower 
angle  on  the  affected  side  its  spine  is  more  hori- 
zontal and  the  lower  ano-le  nearer  the  mid-line  than 
the  upper  and  than  the  corresponding  lower  angle 
on  the  sound  side.  The  patient  is  unable  to  raise 
the  affected  arm  in  front  of  the  body  above  the 
level  of  the  shoulder,  and  to  perform  any  forward 
pushing  movements  ;  any  attempt  to  do  so  at  once 
increases  the  winging',  and  the  whole  scapula  can  be 
pushed  away  from  the  thorax  by  backward  pressure 
on  the  hand  when  the  arm  is  raised. 

When  the  serratus  is  paralysed  alone  the  de- 
formity when  the  arm  is  at  rest  is  hardly  noticeable, 
and  may  be  overlooked  unless  the  rule  is  adopted  of 
marking  out  the  land-marks  on  the  scapula.  The 
patient  is  unable  to  raise  the  arm  above  the  level  of 
the  shoulder  in  front  of  the  body,  and  to  perform 
forward  pushing  movements  above  a  horizontal 
plane  passing  through  the  shoulder ;  attempts  to 
perform  this  latter  movement  causes  the  winging  to 
become  more  marked.  Pushing  movements  below 
this  plane  are  possible. 


214  INJURIES    OF    NERVES 

The  slight  winging  of  scapula,  produced  by 
paralysis  of  the  lower  trapezius  alone,  at  once 
disappears  on  raising  the  arm  above  the  level  of  the 
shoulder  in  front  of  the  bod}^,  thus  throwing  the 
serratus  niagnus  into  action.  It  becomes  increased 
when  attem^Dts  are  made  to  push  below  the  level  of 
the  shoulder. 

Treatment. — In  the  large  proportion  of  cases  the 
injury  is  incomplete  and  does  not  call  for  operative 
interference.  Absolute  rest  to  the  limb  should  be 
ordered,  the  elbow  being  supported.  The  usual 
treatment  with  massage,  etc.,  must  be  carried  out. 
If  the  reaction  of  degeneration  develops  operation 
must  be  considered.  Direct  suture  is  out  of  the 
question,  except  in  the  cases  in  which  the  nerve  is 
injured  in  the  course  of  a  surgical  operation.  In 
the  cases  in  which  the  lesion  is  due  to  jDressure, 
anastomosis  to  the  posterior  cord  should  be  carried 
out  if  necessary,  or  the  sterno-costal  portion  of  the 
pectoralis  major  trans^Dlanted  from  the  arm  to  the 
inferior  angle  of  the  scapula. 

Prognosis. — The  large  proportion  of  these  cases 
recover  without  surgical  intervention  if  treatment  is 
carefully  carried  out. 

The  supra- scapular  nerve.— Injury  to  this  nerve 
alone  is  an  accident  of  great  rarity.  Eleven  cases 
have  been  recorded,  most  of  them  due  to  carrying- 
weights  on  the  shoulder  or  from  falls  on  the  out- 
stretched   hand.      In   two    cases    of    brachial    birth 


SUPRA-SCAPULAR    NERVE  215 

paralysis  I  found  complete  rupture  of  this  nerve  to- 
gether with  the  anterior  primary  division  of  the  fifth 
cervical  nerve  ;  none  of  the  cases  other  than  these 
have  been  verified  by  operation^  and  it  is  probable 
that  in  some^  the  fibres  which  go  to  form  this  nerve 
were  affected  as  they  run  in  the  fifth  anterior 
primary  division. 

Injury  to  this  nerve  affects  the  spinati  muscles. 
These  become  wasted  and  the  spine  of  the  scapula 
unduly  prominent.  External  rotation  of  the  arm, 
though  weak,  is  still  possible,  the  teres  minor  and 
posterior  fibres  of  the  deltoid  carrying  it  out.  But 
the  spinati  muscles  are  usually  affected  with  the 
other  muscles  supplied  from  the  fifth  cervical  nerve. 
In  these  cases  external  rotation  of  the  arm  cannot 
be  performed. 

Treatment. — An  isolated  paralysis  of  the  spinati 
should  be  treated  upon  the  usual  lines;  even  if  com- 
pletely divided  it  is  hardly  of  sufficient  import  to 
call  for  operative  interference.  Electrical  examina- 
tion of  the  infra-spinatus  muscle  is  easy,  but  the 
supra-spinatus  is  covered  by  the  trapezius;  its 
electrical  reactions  cannot,  therefore,  be  satisfactorily 
tested. 

Nerve  to  the  rhomboids. — Isolated  injury  to  this 
nerve  is  almost  unknown  and  is  of  slight  importance; 
accompanying  the  paralysis  of  other  muscles,  it  is  an 
important  localisiug  aid. 

It  may  be  injured  with  the   serratus  magnus  and 


216  INJURIES    OF    NERYES 

lower  trapezius  as  the  result  of  direct  pressure  above 
the  clavicle,  in  penetrating  Avounds  or  divided  during 
the  course  of  operations  upon  the  neck. 

The  deformity  produced  by  paralysis  of  the 
rhomboids  is  characteristic.  On  marking  out  the 
spines  and  lower  angle  of  the  scapula  it  is  seen  that 
the  lower  angle  is  further  from  the  mid-line  than 
the  upper^  the  spine  makes  a  more  acute  angle  with 
the  mid-line  than  the  one  on  the  sound  side,  and  the 
whole  scapula  is  dropped  (vide  Plate  X,  fig.  1). 

Circumflex  nerve. — An  injury  to  this  nerve  is  by  no 
means  so  frequentl}^  met  with  as  the  accounts  in  the 
text-books  would  lead  one  to  believe.  Paralysis  of 
the  deltoid  muscle,  however,  following  an  injury  to 
the  shoulder  is  common,  but  is  due  in  most  cases,  as 
I  have  shown,  to  injury  to  the  fibres  supplying  this 
muscle  as  they  run  in  the  fifth  cervical  anterior 
primary  division,  and  is  usually  accompanied  by 
paralysis  of  the  spinati  muscles.  Most  of  the  so- 
called  examples  of  circumflex  injury  following  a  fall 
or  blow  on  the  shoulder  are  of  this  nature.  In  a 
few  the  wasting  is  secondar}^  to  disease  of  the 
shoulder-joint  and  examination  reveals  no  paralysis. 

The  usual  explanation  given  of  an  injury  to  the 
circumflex  due  to  a  blow  on  the  shoulder  is  that 
the  nerve  receives  an  injury  in  its  intra-muscular 
course  ;  no  such  case  has  come  under  my  notice. 
In  miners  who  lie  for  long  periods  on  the  side  the 
muscle  may  be  paralysed  by  direct  pressure  on  the 


PLATE    X. 


Fig.  1. — To  illustrate  the  deformity  produced  by  division  of  the 
nerve  to  the  rhomboids.     (E,.) 


Fia.  2. — To  show    dropping-  of   humerus    in   paralysis   of   the 
deltoid  and  spinati  muscles. 


To  face  p.  216. 


Adlard  <f  Son,  Impr. 


CIRCUMFLEX    NERVE  217 

terminal  filaments  of  the  nerve^  and  the  nerve  may 
be  involved  as  the  result  of  inflammation  of  the  sub- 
deltoid bursa.  It  is^  however^  more  liable  to  injury 
as  it  passes  round  the  neck  of  the  humerus.  Here 
it  may  be  pressed  upon  by  a  crutch^  the  head  of  the 
humerus  in  sub-glenoid  dislocations^  or  injured  in 
fractures  of  the  neck  of  the  scapula  or  surgical  neck 
of  the  humerus. 

An  injury  to  this  nerve  causes  well-defined 
symptoms.  The  deltoid  is  wasted  and  the  acromion 
process  prominent^  but  the  head  of  the  humerus 
does  not  tend  to  fall  away  from  the  glenoid  cavity 
as  it  does  when  the  spinati  are  affected  in  addition 
{vide  Plate  X^  fig.  2)  ;  this  is  an  important  diagnostic 
pointy  but  unfortunately  it  is  not  always  present, 
the  long  tendon  of  the  biceps  in  some  cases  is 
able  alone  to  keep  the  head  in  j)osition_,  but  in 
the  patient  from  whom  the  illustration  was  taken 
neither  the  biceps  nor  the  clavicular  fibres  of  the 
pectoralis  major  were  paralysed.  The  paralysis  of 
the  deltoid  muscle  is  easy  to  detect  in  recent  cases  ; 
in  old-standing  ones  it  is  by  no  means  so  simple. 
As  pointed  out,  first  by  Duchenne,  later  by  Ross, 
Kennedy  and  Kron,  other  muscles  take  its  place 
and  elevate  the  arm ;  these  are  the  spinati,  the 
clavicular  fibres  of  the  pectoralis  major  and  serratus 
magnus. 

The  paralysis  of  the  teres  minor  cannot  always  be 
determined. 


218  INJUKIES    OF    NEEYES 

Sensory  changes  always  accompany  an  injury  to 
this  nerve  of  sufficient  severity  to  cause  paralysis  of 
the  deltoid.  Complete  division  of  the  nerve  pro- 
duces a  loss  of  epicritic  and  protopathic  sensibility 
over  the  area  seen  in  Plate  XI.  There  is,  as  a  rule, 
no  loss  of  deep  touch.  In  incomplete  lesions  the 
loss  is  correspondingly  less  and  follows  the  usual 
rules. 

Careful  examination  is  necessary  before  coming  to 
the  diagnosis  of  an  injury  to  the  circumflex  nerve. 
If  there  is  no  sensory  change  this  can  certainly  be 
excluded.  All  the  muscles  of  the  shoulder  girdle 
must  be  examined  and  the  condition  of  the  spinati 
specially  noted. 

Treatment.  —  The  injury  is  usually  incomplete 
and  treatment  proceeds  on  the  usual  lines.  But 
even  if  the  lesion  be  complete  and  the  reaction 
of  degeneration  present,  operation  is  by  no  means 
always  necessary.  The  sensory  loss  is  over  an  un- 
important region  and  the  paralysis  may  be  fairly 
well  compensated  by  other  muscles.  The  age  of 
the  patient  and  his  occupation  must  be  considered. 
In  most  cases  sufficient  abduction  is  obtained  by 
training  the  neighbouring  muscles  to  take  the  place 
of  the  deltoid.  If,  hoAvever,  perfect  abduction  is 
essential,  the  nerve  may  be  exposed  and  the  con- 
dition dealt  with  by  operation.  This  is  best  done 
through  an  incision  parallel  to  the  posterior  border 
of  the  deltoid  muscle. 


PLATE    XI. 


Loss  of  sensibility  resulting  from  division  of  circumflex  nerve. 


To  face  p.  218. 


Adlard  S-  Son,  Impr. 


CHAPTER    XV 

Tlie  DiagTiosis  of  Brachial  Plexus  Injuries — Alterations  in  tlie 
Position  of  the  Scapula — Diagnosis  from  Injuries  of  the 
Cervical  Portion  of  Spinal  Cord — Localising  Signs. 

In  making  a  diagnosis  the  following  points  have 
to  be  ascertained  :  the  situation  and  nature  of  the 
lesion^  whether  spina]  cord  or  jDeripheral  nerves, 
whether  above  or  below  the  clavicle,  and  its  exact 
position  in  the  plexus.  As  in  the  case  of  all  other 
nerve  injuries,  the  diagnosis  of  complete  or  incom- 
plete division  must  be  made  from  the  distribution  of 
the  symptoms  and  the  electrical  examination  of  the 
affected  nmscles. 

Time  and  patience  are  needed  to  make  the  diag- 
nosis in  these  cases.  It  is  of  the  utmost  importance 
to  haA^e  the  patient  stripped  so  as  to  expose  the 
whole  of  both  upper  limbs,  including  the  shoulder 
girdle  muscles,  and  the  routine  examination  (vide 
p.  45)  must  be  carried  out. 

The  condition  of  the  muscles  passing  from  the 
trunk  to  the  scapula  is  important.  The  midline  of 
the  body  and  the  spines  and  lower  angles  of  the 
scapula?  must  be  marked  in  ;   only   in  this  way  are 


220  INJURIES    OF    NERYES 

slight  changes  in  position  appreciated.  Alterations 
in  the  position  of  the  scapnla  may  be  clue  to  paralysis 
of  the  trapezius^  serratns  magnns^  or  rhomboids. 
The  most  common  abnormality  consists  in  winging 
of  the  scapnla  ;  this  may  result  from  paralysis  of  the 
lower  trapezius,  of  the  serratns  magnus_,  or  the  two 
combined.  It  is  most  marked  when  both  serratus 
and  trapezius  are  paralysed,  least  in  paralysis  of 
lower  trapezius. 

In  paralysis  of  the  serratus  magnus  the  winging 
is  obvious  and  becomes  more  marked  when  attempts 
are  made  to  push  above  the  level  of  the  shoulder  in 
front  of  the  body.  The  patient  is  unable  to  raise 
the  arm  above  the  head  in  front  of  the  body,  but 
abduction  is  possible.  When  the  lower  trapezius  is 
paralysed  the  scapula  is  tilted  downwards  and  for- 
wards ;  the  whole  bone  is  further  from  the  mid-line 
than  on  the  sound  side,  and  the  upper  angle  than 
the  lower.  The  lower  border  of  the  rhomboideus 
major  is  seen  standing  out  prominently;  this  is  an 
important  point.  The  slight  winging  at  once 
disappears  on  throwing  the  serratus  magnus  into 
action,  and  becomes  more  pronounced  when  the 
patient  attempts  forward  pushing  movements  below 
the  level  of  tlie  shoulder.  The  patient  is  unable,  at 
first,  to  abduct  the  arm  to  more  than  a  right  angle  ; 
later  he  may  be  able  to  do  so.  On  watching  closely 
the  arm  is  seen  to  be  taken  from  the  side  by  the 
deltoid,  then  rotated  out  and  drawn  forwards  by  the 


CHANGES  IN  POSITION  OF  SCAPULA  221 

clavicular    fibres    of  the  pectoralis  major  and  taken 
up  above  the  head  by  the  serratus  magnus. 

The  winging  of  the  scapula  commonly  seen^  due 
to  pressure  above  the  clavicle^  results  from  paralysis 
of  both  serratus  magnus  and  lower  trapezius.  In 
these  cases  the  winging  is  well  marked  and  all 
pushing  movements  in  front  of  the  body  are  im- 
possible. 

The  nerve  to  the  rhomboids  is  rarely  injured. 
The  fifth  cervical  nerve  usually  sujffers  after  it  has 
given  off  this  branchy  but  in  the  patient  from 
whom  fig.  \,  Plate  X^  was  taken  it  was  divided  in  a 
penetrating  wound  above  this  point.  Its  division 
produces  a  characteristic  deformity  of  the  scapula. 
The  lower  angle  is  further  from  the  mid-line  than 
the  upper^  and  the  spine  of  the  scapula  makes  a 
more  acute  angle  with  the  mid-line  than  on  the 
sound  side.  Diagnosis  should  be  easy;  its  recog- 
nition is  of  great  importance  in  localisation. 

The  position  of  the  upper  limb  is  often  indicative 
of  the  injury.  Dropping  of  the  humerus,  with 
elongation,  should  always  be  looked  for ;  it  indicates 
a  supra-clavicular  lesion.  The  position  seen  in  Erb- 
Duchenne  paralysis  and  the  abducted  arm,  when 
this  group  is  spared,  are  also  characteristic,  but  it 
must  be  remembered,  as  already  pointed  out  [vide 
p.  62),  that  certain  of  these  groups  may  be  affected 
in  injuries  of  the  spinal  cord.  The  grouping  of  the 
affected  muscles  is  of  importance  in  the  diagnosis  of 


222  INJURIES    OF    NERVES 

lesions  of  the  plexus  from  those  of  peripheral  nerves ; 
for  exarQj)le^  j)^^^ly^is  ^^  ^-^^  ^^'^  group  of  muscles 
or  the  whole  of  the  intrinsic  muscles  of  the  hand 
alone  could  follow  no  lesion  of  one  peripheral  nerve. 
But  it  is  of  little  importance  in  the  differential  diag- 
nosis of  lesions  of  the  cord  from  plexus  lesions;  both 
these  groups  may  be  due  to  injury  of  anterior  horn 
cells ;  we  must  rely  on  other  signs. 

The  sensory  examination  must  be  carried  out  in 
every  case.  Sensibility  is  always  lost^  and  this  loss 
is  obvious  to  the  patient  and  surgeon,  in  injuries  of 
the  whole  plexus^,  but  this  is  not  the  case  in  injuries 
of  single  anterior  primary  divisions,  although  the 
patient  may  complain  of  alterations  in  sensibility. 
In  lesions  of  the  spinal  cord  the  patient  is  often  un- 
conscious of  any  alteration  of  sensibility  on  the  side 
of  the  body  opposite  to  the  lesion. 

The  diagnosis  of  a  lesion  of  the  plexus  from  one 
of  the  spinal  cord  is  important.  It  is  not  sufficiently 
well  recognised  that  a  lesion  of  the  cervical  portion 
of  the  cord  may  closely  simulate  a  brachial  plexus 
lesion.  It  has  too  long  been  the  custom  to  consider 
an  injury  of  this  part  of  the  cord  as  almost  of 
necessity  fatal,  and  a  broken  neck  synonymous  with 
sudden  death.  But  a  fracture  of  the  cervical  spine 
not  infrequently  occurs  in  which,  as  I  have  pointed 
out,  no  symptoms  suggestive  of  this  accident  are 
present  at  the  time  of  the  accident,  and  it  is  only 
later  that  deformity  occurs. 


DIAGNOSIS  FROM  SPINAL  CORD  INJURY  223 

These  injuries  are  usually  due  to  flexion  : 
For  example,  a  man,  while  carrying  a  weight 
on  his  back,  slips,  or  a  Aveight  from  a  height 
falls  upon  his  back  producing  over-flexion  of  the 
cervical  spine ;  they  may  also  arise  as  hunting 
accidents  or  from  diving  into  shallow  water.  Jonathan 
Hutchinson  as  far  back  as  1866  described  typical 
cases  of  this  nature,  but  considered  that  they  were 
due  to  injury  of  nerve  roots  rather  than  to  the  cord 
itself.  It  is  to  a  great  extent  owing  to  the  work  of 
Thorburn  and  Pao-e  that  we  know  the  nature  of 
these  injuries.  The  former  pointed  out  that  an 
injury  to  the  S23inal  cord  might  occur  without  a 
fracture  from  over-flexion  of  the  spinal  column, 
and  that  it  consisted  in  a  haemorrhage  into  the 
grey  matter,  particularly  in  the  region  of  the  anterior 
horn. 

These  cases  are  by  no  means  uncommon  ;  several 
have  come  under  my  observation.  In  most  instances 
there  are  definite  signs  of  interference  with  the 
functions  of  the  cord  below  the  level  of  the  lesion, 
and  the  case  may  at  first  be  considered  one  of  ''  con- 
cussion ''  of  the  spinal  cord,  and  it  is  not  until  some 
days  have  elapsed  that  the  local  destructive  lesion  is 
manifest.  In  others — and  in  these  most  difticulty 
arises — the  ha3morrhage  is  small,  and  may  lead  to 
but  slight  interference  with  conduction  in  the  cord, 
and  nothing  may  be  noticed  beyond  increased  reflexes 
in  the  lower  limb  of  the  same  side  as  the  lesion. 


224  INJURIES    OF    NERVES 

A  typical  case  of  liaBuiatomyelia  illustrates  well 
tlie  points  given  in  Chapter  Y.  There  is  destruc- 
tion of  a  portion  of  the  anterior  horn;  consequently 
some  muscles,  usually  the  intrinsic  muscles  of  the 
hand,  remain  permanently  paralysed  and  may  give 
the  reaction  of  degeneration.  The  muscles  of  the 
same  side  below  the  seat  of  the  lesion  are  more 
or  less  spastic.  The  reflexes  are  increased  and 
Babinski^s  sign  present  and  there  is  loss  of  pain, 
heat  and  cold  on  the  opposite  side  of  the  body  below 
the  lesion.  Of  this  the  patient  is  often  unaware 
until  his  attention  is  drawn  to  it  by  accident  or 
testing.  It  should  also  be  remembered  that  signs 
of  interference  with  the  cervical  sympathetic  may  be 
present,  the  pupillary  fibres  descending  from  their 
centre  in  the  medulla  being  interrupted  in  the  cord. 
The  following  is  typical  of  this  group  : 

"  A  male,  aged  forty-one  years,  came  to  my  out- 
patient department  at  the  London  Hospital  in 
December,  1906,  on  account  of  abdominal  pain. 
Noticing  that  the  interossei  muscles  of  his  left  hand 
were  wasted,  I  questioned  him  and  found  that  twenty 
years  previously  he  had  struck  his  head  while  diving 
into  shallow  water.  He  lost  230wer  in  his  limbs  at 
once  but  did  not  lose  consciousness  ;  power  returned 
slowly  to  all  except  the  left  leg  and  the  left  hand, 
'j^he  intrinsic  muscles  of  the  left  hand  were  wasted, 
and  except  the  abductor  and  opponens  pollicis  were 
wasted    and    paralysed    and    gave    the   reaction   of 


LOCALISATION  OF  PLEXUS  INJURIES  225 

degeneration;  no  other  muscles  in  the  upper  limb 
were  affected.  He  was  aware  of  no  sensory  change 
and  testino"  revealed  none  on  the  side  of  the  lesion, 
but  on  the  side  opposite  to  the  motor  affection  he  Avas 
analgesic  and  was  insensitive  to  heat  and  to  cold 
from  just  below  the  costal  margin  downwards. 
Tactile  sensibility,  deep  and  light_,  were  perfect/' 

No  difficulty  should  arise  in  the  diagnosis  of  these 
cases  from  lesions  of  the  plexus  if  their  existence 
is  borne  in  mind  and  the  points  mentioned,  re- 
membered. 

There  are  several  important  symptoms  to  aid  in 
the  localisation  of  a  plexus  lesion.  They  are — signs 
of  interference  with  the  cervical  sympathetic,  and 
the  paralysis  of  the  serratus  magnus,  the  rhomboids, 
and  the  spinati  muscles.  It  is  necessary  to  remember 
a  few  anatomical  points  in  relation  to  each  of  these. 
The  white  rami  communicantes  from  the  first  dorsal 
nerve  root  which  enter  the  cervical  sympathetic  are 
given  off  from  its  anterior  primary  division  just 
external  to  the  inter-vertebral  foramen,  so  that  in  an 
injury  involving  the  sympathetic  we  know  that,  as 
far  as  the  first  dorsal  is  concerned,  it  is  impossible 
to  get  above  it. 

The  posterior  thoracic  is  given  off  from  the  fifth, 
sixth,  and  seventh  anterior  primary  divisions,  after  the 
nerves  have  left  the  inter-vertebral  foramina.  The 
nerve  to  the  rhomboids  is  given  off  from  the  fifth 
together    with    the    root    given     to     the     posterior 

15 


226  INJURIES    OF    NERYES 

thoracic.  The  supra-scapular  nerve  arises  from  the 
trunk  formed  by  the  union  of  the  fifth  and  sixth 
anterior  primary  divisions. 

The  value  of  these  facts  in  localisation  is  shown 
by  the  following  case  : 

"A  boy^  aged  fourteen  years_,  sustained  a  severe 
injury  to  his  leff  shoulder  through  a  box  falling- 
upon  it.  When  seen  two  months  later  all  the  muscles 
around  the  shoulder^  in  the  arm^  forearm  and  hand 
were  wasted.  The  muscles  of  the  hand^  forearm  and 
arm  were  paralysed_,  but  the  rhomboids_,  serratus 
magnus  and  trapezius  acted  well  although  the  spinati 
and  pectorals  were  paralysed.  The  palpebral  fissure 
on  the  affected  side  was  narrower  and  the  whole  eje 
somcAvhat  sunken ;  the  pupil  was  smaller  than  on 
the  sound  side.  The  loss  of  sensibility  typical  of  a 
supra-clavicular  lesion  Avas  present.^^ 

The  exact  position  of  the  injury  to  the  nerves  Avas 
easy  of  diagnosis.  The  injury  must  have  affected 
the  upper  and  middle  trunks  of  the  plexus  just 
distal  to  the  point  Avhere  the  long  thoracic  nerve  is 
given  off;  below^  the  injury  must  have  involved  the 
first  dorsal  nerve^  a  localisation  which  the  subsequent 
operation  proved  to  be  correct. 

Atrophy  and  paralysis  of  the  deltoid  are  common 
after  injuries  in  the  region  of  the  shoulder.  The 
following'  is  a  good  example  of  this  type  of  injury  : 

"  G.  B — ,  aged  forty-nine  years,  came  under  my 
care  at  the  London  Hospital,  complaining  of  inability 


DELTOID    PARALYSIS  227 

to  raise  the  rio-lit  arm  from  the  side.  Nine  months 
previously  he  had  fallen  on  the  point  of  his  shoulder. 

'^The  spinati  and  deltoid  were  wasted  and  paralysed 
and  gave  the  reaction  of  degeneration.  The  biceps, 
brachialis  anticus  and  supinator  longus  were  un- 
affected.     There  was  no  sensory  loss. 

"  On  April  4th,  1905,  I  explored  the  plexus  above 
the  clavicle  and  found  a  scar  in  the  upper  part  of 
the  fifth  cervical  anterior  primary  division,  just 
before  it  joins  with  the  sixth  ;  this  scar  was  adherent 
to  the  tissues  above.  After  freeing  I  stimulated  it 
with  the  interrupted  current,  and  found  that  the 
biceps  and  supinators  contracted  vigorously  but  not 
the  deltoid  or  spinati." 

The  paralysis  of  the  spinati  in  these  cases  is  often 
overlooked  and  the  condition  considered  due  to  an 
injury  to  the  circumflex  nerve.  To  avoid  error  the 
examination  must  be  thorough,  and  the  condition  of 
all  the  muscles  innervated  by  the  fifth  cervical  nerve 
investigated.  The  sensibility  of  the  area  on  the 
outer  surface  of  the  arm  supplied  by  the  circumflex 
nerve  must  be  tested.  The  rule  can  be  laid  down 
that  paralysis  of  the  deltoid  without  sensory  change 
is  due  to  interference  with  the  functions  of  the  fifth 
cervical  nerve  and  not  with  the  circumflex ;  when- 
ever this  nerve  is  injured  there  is  imjoairment  or  loss 
of  sensibility. 

The  diagnosis  between  a  complete  and  an  incom- 
plete injury  of  the  plexus  may  not  be  so  simple  as  in 


228  INJURIES    OF    NERVES 

tlie  case  of  injiuy  to  one  peripheral  nerve.  From 
tlie  sensory  standpoint  it  must  be  remembered  tliat 
isolated  injury  of  an  anterior  primary  division  is 
rarely  accompanied  by  sensory  change^  consequently 
we  have  to  rely  entirely  on  our  examination  of  the 
muscles.  It  must  also  be  borne  in  mind  that  incom- 
plete interruption  of  continuity  of  the  fifth  cervical 
may  lead  to  complete  division  of  those  fibres  which 
supply  the  spinati  and  deltoid  with  resulting  reaction 
of  degeneration  in  these  muscles. 

A  knowledge  of  the  electrical  reactions  associated 
mth  incomplete  division  is  necessary.  The  following 
is  an  illustrative  case  : 

"  C.  R — ,  aged  nineteen  years^  was  admitted  into 
the  London  Hospital  under  my  care  for  operation  as 
a  case  of  traumatic  Brb^s  paralysis_,  on  November  7th^ 
1905.  Three  months  previously  he  had  fallen  off 
his  bicycle^  pitching  on  to  the  side  of  his  head. 
Bruising  came  out  in  the  neck  some  days  after  the 
accident. 

''  The  upper  limb  was  in  the  position  typical  of  this 
injury^  and  the  spinati^  deltoid,  biceps  and  supinators 
were  wasted  and  paralysed.  They  did  not  react  to 
the  interrupted  current_,  but  reacted  in  the  typical 
manner  to  the  constant_,  briskly  to  the  normal  pole 
and  with  a  smaller  current  than  was  necessary  to 
produce  contraction  in  the  muscles  of  the  sound 
limb.^^ 

Had  they  given  the    reaction   of    degeneration    I 


INCOMPLETE   DIVISION  229 

sliould  certainly  have  operated  and  resected  the 
damaged  portion  of  the  nerve.  He  was  treated  by 
massage  and  exercises,  and  at  the  end  of  nine 
months  from  the  date  of  the  injury  no  difference 
could  be  told  on  superficial  examination  between  the 
two  limbs. 


CHAPTEE    XVI 

Nerves  of  the  U]3per  Limb  (exclnding  Bracliial  Plexus  and  those 
supplying  Shoulder  G-irdle  Muscles) — Musculo-cutaneous 
Nerve — Musculo-spiral  Nerve  :  Method  of  Injury  :  Motor 
Symptoms :  Sensory  Symptoms :  Division  without  Loss  of 
Sensibility — Eadial  Nerve — Ulnar  Nerve  :  Method  of  Injury  : 
Injury  in  Three  Positions  :  True  and  False  Adduction  of  the 
Thumb :  Eecovery  and  Prognosis :  Injuries  in  Fractures : 
recent ;  old — Dislocation  of  the  Ulnar  Nerve — Examination 
and  Diagnosis  of  Ulnar  Injuries — Median  Nerve  :  Method  of 
Injury :  Sensory  Symptoms :  Motor  Symptoms :  Eecovery 
and  Prognosis — Simultaneous  Injury  of  Median  and  Ulnar  : 
Method  of  Injury :  Symptoms :  Method  of  Eecovery  and 
Prognosis. 

Musculo-cutaneous  nerve. — This  nerve^  wliicli  con- 
tinues the  outer  cord  of  the  brachial  plexus,  after 
the  outer  head  of  the  median  has  been  given  olf^ 
supplies  the  coraco-brachialis  and  biceps  muscles, 
with  the  brachialis  anticus  in  part ;  it  then  becomes 
cutaneous  and^  as  the  external  cutaneous  nerve  of  the 
forearm^  supplies  the  pre-axial  (radial)  side  of  the 
forearm  on  its  anterior  (flexor)  and  posterior 
(extensor)  surfaces. 

Isolated  injury  of  the  trunk  of  this  nerve  is  rare  ; 
only  fifteen  examples  have  been  recorded^  and  eleven 
of  these  were  due  to  injury  in  the  removal  of 
tumours  and  the  result  of  gunshot  wounds.       On  the 


MUSCULO-CUTANEOUS    NERVE        281 

other  hand  its  branches^  particularly  the  anterior 
division  of  the  external  cutaneous,  are  not  infre- 
quently affected,  and  filaments  are  often  divided  in 
association  with  other  nerves  in  wounds  in  the  resrion 
of  the  wrist  and  forearm. 

Symptoms. — Complete  division  of  this  nerve  pro- 
duces paralysis  of  the  coraco-brachialis,  of  the  biceps, 
and  of  part  of  the  brachialis  anticus  muscle.  No 
•movements  are  abolished,  and  it  is  only  by  the  investi- 
gation of  the  action  of  the  individual  muscles 
supplied  by  the  nerve  that  the  diagnosis  can  be 
made.  Flexion  and  supination  of  the  forearm  are 
weak,  but  can  be  performed.  The  foi'earm  is  flexed 
in  the  pronated  position,  by  the  supinator  longus 
and  the  extensor  carpi  radialis  longior,  in  the 
supinated,  by  that  portion  of  the  brachialis  anticus 
supplied  by  the  musculo-spiral  nerve.  Supination 
can  be  weakly  performed  by  the  supinator  brevis. 

Sensibility  to  light  touch  and  to  prick  are  lost 
over  the  pre-axial  half  of  the  forearm.  Deep  touch 
is  not  affected.  On  the  anterior  surface  of  the  forearm 
the  boundary  between  sensitive  and  insensitive  areas 
is  extremely  well  defined,  and  is  the  same  for  epicritic 
and  for  protopathic  sensibility,  corresponding  to  a 
line  drawn  upwards  from  the  axis  of  the  ring  finger 
to  the  tendon  of  the  biceps  at  the  bend  of  the  elbow. 
This  border  varies  little  from  patient  to  patient.  On 
the  posterior  (extensor)  surface,  on  the  other  hand, 
the   border  is  sinuous  and  ill-defined,  and  varies  in 


232  INJURIES    OF    NERVES 

individual  patients  with  tlie  size  of  the  lower 
external  cutaneous  branch  of  the  musculo-spiral,  and 
fades  gradually  into  the  normal  sensibility  of  the 
post-axial  half  of  the  posterior  surface. 

vSection  of  the  anterior  or  posterior  branches  of 
this  nerve  alone  usually  fails  to  jDroduce  any 
alteration  in  sensibility.  I  have  divided  the  anterior 
and  the  posterior  branch  in  different  patients^  and 
failed  to  produce  any  sensory  loss  that  could  be  dis- 
covered even  with  the  most  careful  testings  and  the 
patient  suffered  from  no  subjective  symptoms. 

The  musculo-spiral  nerve. — This  nerve  is^  from  the 
surgical  point  of  view,  one  of  the  most  important  in 
the  body.  It  shares  with  the  median  and  the  ulnar 
the  distinction  of  being  more  often  affected  by  injurv 
than  any  other  nerve.  It  is  also  the  nerve  upon 
which  plastic  operations  for  the  restoration  of  ana- 
tomical continuity  have  to  be  most  often  carried  out. 
The  result  of  division  of  this  nerve  is  striking,  and 
its  injury  is  seldom  overlooked. 

The  nerve  is  most  often  involved  in  the  lower 
third  of  the  arm;  only  in  crutch,  ansesthetic,  ^''Satur- 
day-night ''  paralj^ses  and  the  rare  penetrating 
wounds  is  it  affected  elsewhere. 

The  majority  of  the  injuries  are  physiological, 
usually  from  direct  pressure,  the  result  of  fractures 
of  the  humerus,  and  that  causiug  "  crutch  ^'  and 
^'  anaesthetic "  paralysis  ;  it  is  rarely  divided  by  a 
penetrating  wound,  but  I  have  known  the   accident 


MUSCULO-SPIEAL    NERVE  238 

happen  during  the  course  of  wiring  an  ununited 
fracture  of  the  humerus  {vide  p.  237).  Injury  to 
the  musculo-spiral  nerve  sometimes  results  from  a 
forward  dislocation  of  the  head  of  the  radius  ;  one 
such  case  has  come  under  my  care  and  a  similar  one 
has  been  recorded  by  Borchard. 

The  posterior  interosseous  branch  may  suffer  in 
dislocations  of  the  upper  end  of  the  radius  and  in 
fractures  of  its  neck^  and  has  been  divided  as  it  is 
passing  through  the  supinator  brevis  in  operations 
upon  old  dislocations  and  fractures.  The  radial 
nerve  may  be  divided  in  penetrating  wounds  in  the 
region  of  the  wrist^  usually  in  association  with 
branches  of  the  external  cutaneous. 

In  hospital  practice^  sleep  and  Saturday-night 
paralyses  are  common^  due  to  direct  pressure  upon 
the  nerve.  Slight  weakness  in  the  muscles  supplied 
by  the  musculo-spiral  nerve  and  tingling  in  its 
sensory  distribution  are  common^  and  have  been 
experienced  by  all  who  have  fallen  asleep  with  an 
arm  hanging  over  the  back  of  a  chair.  But  the 
discomfort  produced  is  sufficient  to  arouse  a  normal 
individual,  and  the  paralysis  is^  therefore_,  rare  and 
transient.  But  it  is  otherwise  when  the  patient  is 
under  the  influence  of  alcohol ;  paralysis  is,  in  this 
condition,  common  as  the  result  of  direct  pressure,  and 
constitutes  the  sleep  and  Saturday-night  paralyses. 

Crutch  paralysis  of  the  musculo-spiral  nerve  is 
often  seen  ;  it  may  be  avoided  by  padding  the  head 


234  INJUEIES    OF    NERYES 

of  tlie  crntcli  and  employing  cross  pieces  in  order 
that  tlie  weight  of  the  body  may  be  taken  by  the 
arms  as  well  as  the  axilla. 

Injury  to  the  nerve  as  the  result  of  a  fractured 
humerus  is  common.  Bruns  found  inyolvement  of 
the  nerve  in  8  per  cent,  of  all  cases  of  fracture  of 
the  humerus^  and  these  figures  do  not  exaggerate  its 
frequency^  in  my  experience^  although  Reithus  found 
it  only  in  4  per  cent.  It  suffers  most  often  in  frac- 
tures involving  the  lower  and  middle  thirds.  It  may 
be  injured  at  the  time  of  the  accident — primary^  or 
involved  later — secondary  ;  the  latter  is  probably  the 
more  common.  In  the  j^rimary  cases  the  injury  may 
be  anatomical  or  physiological^  though  the  latter  is 
the  more  usual.  The  nerve  may  be  lacerated^ 
ruptured^  pressed  upon  by,  or  between,  the  ends  of 
the  bone^  or  contused  ;  there  is  no  symptom  that  will 
tell  us  which  has  happened,  and,  at  first,  if  the 
injury  is  complete  or  incomplete. 

In  the  secondary  cases  the  nerve  may  be  em- 
bedded in  fibrous  tissue  or  callus,  or  pressed  upon, 
or  stretched  over,  the  displaced  end  of  a  bone. 

Motor  symptoms. — The  appearance  produced  by 
paralysis  of  the  muscles  supplied  by  this  nerve  is 
characteristic:  the  wrist  is  helpless  and  dropped,  and 
there  is  a  marked  prominence  on  the  dorsum  of  the 
hand  if  the  position  has  persisted  for  some  weeks, 
due  to  overstretching  of  the  dorsal  ligaments  of  the 
wrist  and  subluxation  of  the  carpus. 


MUSCULO-SPIRAL    NERYE  235 

The  patient  is  unable  to  extend  the  wrist  owing  to 
the  paralysis  of  the  extensores  carpi  ulnaris  et 
radiales ;  the  paralysis  of  the  extensor  communis 
digitorum  makes  extension  of  the  fingers  at  the 
metacarpo-phalangeal  joints  impossible.  On  attempt- 
ing this  movement  the  wrist  becomes  flexed  owing 
to  the  synergic  action  of  the  carpal  flexors,  and  the 
fingers  often  become  extended  at  the  inter-phalangeal 
joints  and  flexed^  and  the  metacarpo-phalangeal  by 
the  unopposed  action  of  the  interossei  and  lumbri- 
cales,  which  usually  act  with  the  common  extensor 
in  extension  of  the  fingers.  All  the  extensor  muscles 
of  the  thumb  are  paralysed  and  extension  of  the 
terminal  ^^halanx  of  the  thumb  is  always  impossible, 
but  care  must  be  taken  in  inter|Dreting  the  move- 
ment which  takes  place  at  the  metacarpo-phalangeal 
joint ;  the  abductor  pollicis  is  attached  to  the  outer 
side  of  the  base  of  the  first  phalanx  and  often  sends 
a  slip  to  the  tendon  to  the  extensor  longus  pollicis, 
its  contraction  may  produce  a  movement  resembling 
extension,  but  palpation  over  the  tendons  of  the 
extensors  of  the  thumb  will  at  once  reveal  its  nature. 
Paralysis  of  the  triceps  is  unusual,  the  nerve  usually 
being  involved  below  the  point  at  which  its  branches 
of  suppl}^  are  given  off. 

Paralysis  of  the  triceps  is  easily  recognised  ; 
active  extension  of  the  forearm  is  impossible. 

Sensory  symj)toms. — It  has  become  one  of  the 
commonplaces    of    surgery    that    the    musculo-spiral 


236  INJURIES    OF    NERVES 

nerve  may  be  divided  without  causing  any  loss  of 
sensibility.  Savory  first  recorded  this  in  the 
following  careful  manner  : 

'^When  testing  that  portion  of  the  skin  of  the 
hand  which  is  supplied  by  branches  of  the  radial 
nerve  we  were  not  a  little  astonished  to  find  that  it 
was  but  little  impaired.  When  the  skin  .  . 
was  lightly  pricked  the  man  cried  out  sharply.  He 
could  distinguish  in  the  same  region  two  points  of 
contact  when  they  were  not  more  than  an  inch  apart, 
both  in  the  lono*   and  in  the   transverse  axis  of  the 

o 

hand;  but  when  they  were  closer  than  this  on  any 
part  of  the  back  of  either  hand  or  forearm  he  con- 
fused them,  and,  indeed,  in  comparing  the  sensibility 
of  this  region  with  that  of  the  inner  portion  of  the 
back  of  the  hand  and  two  inner  fingers,  or  with  the 
corresponding  part  of  the  opposite  hand,  no  very 
striking  difference  could  be  detected.  All  portions, 
too,  of  the  back  and  sides  of  the  middle  finger 
appeared  to  be  equally  sensitive.  He  could  dis- 
tinguish also  between  contact  of  hot  and  cold  bodies 
in  this  region  as  well  as  in  other  parts. '^ 

Many  similar  cases  have  been  recorded.  Among 
them  are  two  reported  by  Kennedy,  in  which  the 
nerve  was  divided  in  the  lower  third  of  the  arm 
without  producing  any  marked  sensory  change ;  one 
recorded  by  Parry,  in  which  two  inches  of  the  nerve 
was  destroyed  without  producing  any  definite  loss  of 
sensibility;  and  Ledderhose  reported  a  case  in  which 


MUSCULO-SPIRAL    NERYE  237 

the  nerve  was  ruptured  as  the  result  of  a  compound 
fracture  of  the  humerus.  The  following  is  another 
case  of  this  nature  : 

"  A  hoj,  aged  nine  years^  came  under  my  care  on 
account  of  musculo-spiral  paralysis  following  opera- 
tion on  a  mal-united  fracture  of  the  humerus.  At 
the  operation  I  discovered  that  the  nerve  had  been 
completely  divided  just  above  its  bifurcation.  Both 
before  and  after  I  had  performed  secondary  suture  I 
was  unable  to  find  any  sensory  change ;  the  compass 
test  was  perfectly  appreciated  and  minor  degrees  of 
heat  and  cold  discriminated  and  no  subjective 
symptoms  were  present. ^^ 

It  is  obvious  that  complete  division  of  the  musculo- 
spiral  nerve  in  its  lower  third  produces  no  alteration 
in  the  sensibility  of  the  forearm  and  dorsum  of  the 
hand,  and  this  is  the  position  in  which  the  nerve  is 
most  often  injured.  But  division  above  the  point  at 
which  its  external  cutaneous  branches  are  given  off, 
or  division  in  the  lower  third  together  with  injury  to 
these  branches  or  to  the  posterior  division  of  the 
external  cutaneous  nerve  of  the  forearm  (musculo- 
cutaneous), produces  a  definite  loss  of  sensibility  on 
the  dorsum  of  the  hand.  But  the  extent  and  degree 
of  this  loss  varies  accordino-  to  the  relative  size  of 
the  posterior  branch  of  the  external  cutaneous. 
Fig.  12  shows  the  usual  loss  resulting  from  division 
of  the  nerve  in  the  upper  third  of  the  arm.  The 
diagram  was  taken  from  two  patients  in  whom  the 


238 


IISVURIES    OF    NERVES 


nerve  was  severed  in  the  axilla  as  the  result  of  a 
gunshot  wound,  and  corresponds  with  that  recorded 
by  Clement  Lucas_,  Kennedy  and  Roger. 

Thus,  division  of  the  nerve  above  the  point  at 
which  its  external  cutaneous  branches  are  given  oft" 
produces  a  loss  of  sensibility  on  the  dorsum  of  the 
hand.  The  loss  is  of  both  epicritic  and  protopathic 
sensibility,  the  former  slightly  larger  in  extent  than 


Fig.  12. — Loss  of  sensibility  produced  by  division  of 
musculo-spiral  nerve  in  tlie  upper  third  of  the  arm. 
Dotted  area  designates  incomplete  loss. 


the  latter,  especially  towards  the  radial  side  of  the 
hand.  There  is  no  loss  of  deep  touch.  Towards 
the  ulnar  side  the  loss  of  both  forms  of  sensibility  is 
well  defined,  but  on  the  radial  it  fades  away  into  the 
normal  sensibility  of  the  palm.  Instances  have  been 
recorded  in  which  a  loss  of  sensibility  has  been 
present  in  the  forearm ;  I  have  not  observed  this 
and   believe  that  it  only   occurs  when  the  posterior 


KADIAL    NERVE 


239 


branch    of    the    external     cutaneous    is    divided    in 
addition  to  the  whole  musculo-spiral. 

The  radial  nerve. — As  would  be  anticipated,  section 
of  this  nerve  in  the  upper  two  thirds  of  the  forearm 
produces  no  loss  of  sensibility.  I  have  had  the 
opportunity  of  examining  patients  in  whom  portions 
of  this  nerve  have  been  removed  for  nerve  trans- 
plantation   without    causing    sensory    loss.      On    the 


Fig.  13. — To  illustrate  the  loss  of  epicritic  sensibility  pro- 
duced by  division  of  the  radial  nerve  in  the  loAver  third 
of  the  forearm. 


other  hand,  division  in  the  lower  third  of  the  forearm, 
after  it  has  become  associated  with  branches  from 
the  posterior  branch  of  the  external  cutaneous  nerve 
has  a  definite  effect  on  sensibility.  Fig.  13  is  taken 
from  a  patient  in  whom  I  divided  the  nerve  just 
after  it  had  passed  beneath  the  tendon  of  the 
supinator  longus.  This  produced  a  loss  of  sensibility 
to   light  touch;  with   a  well-defined  border  towards 


240  INJURIES    OF    NERVES 

tlie  thenar  eminence  and  on  both  sides  of  the  thumb, 
bat  on  the  ubiar  side,  ill-defined,  and  fading  away 
into  the  normal  sensibility  of  the  dorsum  of  the 
hand  ;  there  was  no  loss  of  protopathic  sensibility. 
This  corresponds  to  the  result  seen  in  several 
examples  of  accidental  section  in  this  situation  that 
have  been  under  my  care. 

But  wounds  of  the  dorsal  surface  of  the  wrist  and 
forearm  often  produce  a  larger  area  of  loss,  a  loss  of 
both  protopathic  and  epicritic  sensibility,  deep  sensi- 
bility remaining  intact.  In  these  cases  the  external 
cutaneous  nerve  or  its  posterior  branch  have  been 
divided  in  addition  to  the  radial,  and  in  some  cases 
also,  some  of  the  fibres  of  the  lower  external  cutaneous 
branch  of  the  musculo-spiral. 

Division  of  the  external  cutaneous  nerve  or  of  its 
posterior  branch,  in  addition  to  the  radial,  produces 
an  area  of  loss  of  epicritic  and  protopathic  sensibility 
well  defined  towards  the  thenar  eminence,  ill  defined 
and  of  varying  extent  towards  the  ulnar.  Fig.  14 
was  taken  from  a  patient  in  whom,  as  the  result  of 
an  accidental  wound,  the  radial  and  external  cuta- 
neous nerves  were  divided  in  the  lower  third  of  the 
forearm,  and  corresponds  exactly  to  that  found  when 
these  two  nerves  were  intentionally  divided  on  two 
occasions.  By  comparison  with  Fig.  12  we  see  the 
extent  of  skin  usually  supplied  by  the  descending 
branch  of  the  musculo-spiral. 

Simultaneous  division   of  the   radial  and   external 


EADIAL  AND  EXTERNAL  CUTANEOUS     241 


cutaneous  nerves  in  any  part  of  their  course  produces 
a  curious  dissociation  of  sensibility.  In  Fig.  14  it 
will  be  seen  that  this  area  is  roughly  triangular  in 
shape.  Prick  and  the  extreme  degrees  of  tempera- 
ture cannot  be  appreciated  over  the  ^Yhole  affected 
area,  but  light  touches  with  cotton-wool  and  the 
minor  degrees  of  temperature  can  be  recognised  over 
the  triangular  area  by   an  intelligent  patient.      The 


Fig.  14. — To  illustrate  the  loss  of  sensibility  produced  by- 
section  of  the  radial  and  external  cutaneous  nerves.  The 
triangular  area,  bounded  towards  the  ulnar  side  by  a 
continuous  line,  towards  the  radial  by  a  dotted  line, 
represents  the  area  sensitive  to  light  touch  but  insensi- 
tive to  i^rick. 

lower  external  cutaneous  branch  of  the  musculo- 
spiral  appears^  therefore,  to  supply  a  larger  area  with 
epicritic  than  with  protopathic  fibres.  This  forms 
no  exception  to  the  rules  already  laid  down^  that 
division  of  a  peripheral  nerve  produces  a  loss  of 
sensibility  to  light  touch  greater  in  extent  than  that 
of  sensibility  to  prick^  for  when  the  whole  musculo- 
spiral  is  divided  this  is  the  case. 

16 


242  INJURIES    OF    NERYES 

The  so-called  "  radial  area  "  of  tlie  dorsum  of  the 
hand  is  supplied  with  epicritic  and  protopathic 
sensibility  by  the  following  nerves^  and  in  order  to 
produce  a  loss  of  these  forms  of  sensibility  over  the 
whole  area  Avitli  well-defined  boundaries  it  is  neces- 
sary to  divide  them  all :  the  radial  and  lower  external 
cutaneous  branches  of  the  musculo-spiral  and  the 
posterior  branch  of  the  external  cutaneous  (musculo- 
cutaneous). But  even  after  division  of  these^  deep 
sensibility  is  unaffected^  and  such  an  injury  as  this 
allows  deep  sensibility  to  be  accurately  studied. 

Prognosis  and  treatment. — As  already  pointed  out 
in  siDeaking  of  primary  injury  of  this  nerve  in  fractures 
of  the  humerus,  it  may  be  impossible,  as  in  other 
subcutaneous  nerve  injuries,  to  say  at  first  what  the 
degree  of  injury  is.  Paralysis  of  the  muscles  sup- 
plied by  it  may  be  produced  by  an  injury  so  slight 
that  recovery  is  almost  perfect  in  a  week  ;  on  the 
other  hand  a  similar  paralysis,  so  far  as  physical 
signs  are  concerned,  may  be  followed  by  the 
development  of  the  reaction  of  degeneration,  and 
no  recovery  ensue  until  continuity  has  been  re-estab- 
lished by  operation.  Careful  electrical  testing  is 
necessary  in  order  to  give  a  prognosis.  In  most  of  the 
Saturday-night,  crutch,  and  post-anaesthetic  palsies, 
the  muscles  retain  their  irritability  to  the  interrupted 
current  throughout,  and  recovery  may  be  confidently 
anticipated  in  from  seven  to  twenty-eight  days. 
When  the  pressure  upon  the  nerve  has  been  greater 


MUSCULO-SPIRAL    NERVE  243 

or  has  lasted  for  a  longer  time,  the  typical  reactions 
of  incomplete  division  are  23resent.  Kecovery,  if  the 
cause  has  been  removed,  commences  in  these  cases 
in  from  four  to  twelve  weeks.  If  the  reaction  of 
degeneration  is  present,  recovery  rarely  ensues  with- 
out resection  of  the  damaged  portion  and  end-to-end 
suture. 

After  primary  or  secondary  suture  the  prognosis 
is  better  than  after  suture  of  any  other  nerve  of  the 
body.  This  is  probably  an  accident  of  supply  only ; 
no  sensory  loss  is  ^Dresent  after  division  in  the  usual 
situation;  in  the  rare  instances  in  which  the  nerve  is 
divided  above  the  origin  of  its  external  cutaneous 
branches,  the  area  of  altered  sensibility  is  situated 
over  a  region  Avhere  it  will  in  no  way  impair  the 
efficiency  of  the  hand  for  work.  The  muscles  sup- 
plied by  the  nerve  are  not  employed  in  fine  move- 
ments of  the  fingers  to  the  same  degree  as  those 
supplied  by  the  median  or  ulnar.  Perfect  recovery 
may  be  expected  in  about  a  year  from  the  time  of 
suture. 

The  march  of  recovery  after  incomplete  division 
and  after  complete  division  and  suture  is  the  same. 
Those  muscles  nearest  the  seat  of  the  lesion  first  regain 
their  voluntary  power.  When  the  nerve  is  divided 
in  the  lower  third  of  the  arm  the  supinator  longus 
first  recovers,  followed  in  a  short  time  by  the 
extensors  of  the  wrist,  then  the  common  extensor  of 
the  fingers,  and  finally  those  of  the  thumb. 


244  INJURIES    OF    NERVES 

During  the  whole  period  of  paralysis  the  affected 
muscles  must  be  kept  from  overstretching  ;  the  wrist 
must  not  be  allowed  to  remain  in  the  dropped 
position  but  supported  on  a  splint.  The  usual  after- 
treatment  must  not  be  neglected. 

If  the  paralysis  result  from  the  j)ressure  of 
crutches  suitable  crutches  must  be  ordered  that  will 
exercise  no  pressure  upon  the  nerve. 

Examination  must  be  made  in  all  fractures  of  the 
humerus  for  the  signs  of  nerve  injury.  The  primary 
cases_,  though  the  less  numerous,  are  the  more 
serious,  and  should  be  explored  as  soon  as  possible. 
If  this  were  done  the  iieed  for  nerve  transplantation 
after  injury  would  rarely  arise.  In  most  of  the 
cases,  however,  the  joaralysis  is  not  discovered  until 
the  s^Dlints  have  been  removed.  If  the  signs  point 
to  a  complete  division  of  the  nerve  operation  should 
not  be  delayed.  The  surgeon  should  be  prepared  to 
deal  with  a  gap  in  the  nerve  that  cannot  be  bridged 
over  by  nerve  stretching.  In  these  cases  the  radial 
nerve  should  be  used  {vide  p.  96).  Resection  of 
bone  should  be  reserved  for  cases  of  ununited  frac- 
ture complicated  by  division  of  the  nerve,  which  will 
necessitate  freshening  the  ends  of  the  bone.  The 
bone  should  never  be  divided  solely  for  the  purpose 
of  shortening  the  limb. 

In  most  cases  of  secondary  involvement,  and  in 
those  cases  in  which  the  injury  is  discovered  on  the 
removal  of  splints,  the  reactions  are  those  of  incom- 


INTERNAL    CUTANEOUS    NERVE       245 

plete  division ;  if  the  involvement  is  certainly 
secondary,  operation  should  be  done,  the  compressing 
agent  removed  and  the  nerve  freed  and  wrapped. 
The  operation  of  neurolysis  was  first  performed  by 
Busch  in  I860,  followed  shortly  by  Oilier.  Employed 
in  suitable  cases — those  in  which  the  reactions  are  in- 
complete— recovery  commences  in  from  a  few  days  to 
a  few  weeks  if  the  affected  muscles  are  kept  relaxed. 
Relapses  have  occurred  due  to  the  formation  of 
adhesions  around  the  freed  nerve ;  in  one  recorded 
case  the  nerve  was  freed  four  times.  This  recur- 
rence may  be  23revented  by  always  protecting  the 
nerve  by  some  form  of  wrapping. 

The  internal  cutaneous  nerve. — This  nerve  is  rarely 
injured  alone.  It  is  occasionally  divided  in  the  arm 
as  the  result  of  penetrating*  wounds  ;  or  one  of  its 
branches — usually  the  anterior — may  be  divided  in 
the  forearm,  in  most  cases  in  conjunction  with  the 
ulnar. 

The  nerve  supplies  a  well-defined  area  on  the 
flexor  and  extensor  surfaces  of  the  forearm,  on  its 
post-axial  (ulnar)  side.  The  loss  of  epicritic  sensi- 
bility has  well-defined  borders  corresponding,  on  the 
flexor  surface,  to  a  line  drawn  from  the  tendon  of 
the  biceps  to  the  axis  of  the  ring  finger,  and,  on  the 
dorsum,  from  the  olecranon  to  the  axis  of  the  same 
finger.  The  borders  for  the  loss  of  epicritic  and 
protopathic  sensibility  are  almost  coterminous  in  the 
upper  part  of  the  forearm,  but  fall  away  considerably 


246  INJURIES    OF    NERYES 

below.  But  it  is  rarely  that  the  nerve  is  iiijared  in 
such  a  way  as  to  completely  divide  its  trunk  above 
the  lower  third  of  the  arm.  More  often  the  injury 
is  below  this  }3oint  and  severs  its  anterior  or  posterior 
branch  only.  This  produces  a  loss  of  epicritic  sensi- 
bility over  the  front  or  back  of  the  forearm  with  no 
loss  of  protopathic  sensibility.  If  the  anterior  branch 
is  divided  the  loss  is  limited  by  a  well-defined  border 
on  the  flexor  surface  of  the  forearm^  but  gradually 
merges  into  the  normal  sensibility  of  the  extensor 
surface  by  a  band  of  diminished  sensibility.  Similarly^ 
division  of  the  posterior  branch  causes  epicritic  loss 
of  sensibility  on  the  extensor  surface  of  the  forearm, 
sharply  defined  on  its  radial  side,  gradually  fading 
into  the  normal  sensibility  of  the  ulnar  border  of 
the  forearm. 

Ulnar  nerve. — This  nerve  is  more  often  divided  in 
accidental  Avounds  than  any  other  nerve.  It  may 
be  injured  in  a  23enetrating  wound  in  any  part  of  its 
course,  but  this  variety  of  injury  is  usually  in  the 
neighbourhood  of  the  wrist,  the  result  of  broken 
glass ;  penetrating  wounds  on  the  dorsum  or  ^^alm 
may  occasionally  divide  its  deep  division.  Behind 
the  internal  condyle  the  injury  may  be  caused  by  a 
direct  blow,  but  more  often  complicates  a  fracture 
or  dislocation  in  the  region  of  the  elbow.  Penetrating- 
wounds  in  this  region  are  unusual,  but  the  nerve  has 
been  injured  during  the  course  of  excision  of  the 
elbow.      It  occasionally  suffers  in  certain  occupations 


ULNAR    NERVE  247 

entailing  constant  movements  at  the  elbow,  such  as 
glass-workers,  cigarette-makers . 

The  effect  of  division  of  the  ulnar  nerve  must 
be  studied^  as  it  arises  in  three  situations — (1)  at  or 
above  the  point  at  which  the  motor  branches  to  the 
forearm  muscles  are  given  off  (at  the  elbow),  and  at 
the  wrist  (2)  above  and  (o)  below  the  point  at  which 
its  dorsal  branch  is  given  off. 

At  the  elhoiD. — Division  of  the  nerve  at  or  above 
the  elbow  produces  paralysis  of  the  following 
muscles  :  the  flexor  carpi  ulnaris,  the  ulnar  half  of 
the  flexor  profundus  digitorum,  all  the  interossei, 
the  two  inner  lumbricales  and  the  adductors  of  the 
thumb. 

The  hand  assumes  a  characteristic  position  and 
it  is  easy  to  say  the  ulnar  nerve  has  been  injured, 
but  difficulty  is  sometimes  experienced  in  discovering 
the  paralysis  of  the  individual  muscles.  The  index 
and  middle  fingers  are  extended  at  the  metacarpo- 
phalangeal joints  owing  to  paralysis  of  the  interossei 
muscles  attached  to  them ;  the  little  and  ring  fingers 
are  hyper-extended  at  these  joints  in  consequence  of 
paralysis  of  the  lumbricales  in  addition.  All  the 
fingers  are  flexed  at  the  interphalangeal  joints,  the 
flexion  being  most  marked  in  the  little  and  ring- 
fin  p-ers ;   the  little  fino-er  is  held  abducted. 

On  flexing  the  Avrist  the  hand  is  slightly  tilted 
to  the  radial  side.  But  the  paralysis  of  the  flexor 
carpi  ulnaris  is  often  compensated  by  the  action  of 


248  INJURIES    OF    NERVES 

tlie  jDalmaris  longus_,  and  careful  palpation  over  the 
insertion  of  the  former  muscle  into  the  pisiform 
bone  may  be  necessary  in  order  to  make  the 
diagnosis.  The  little  and  ring  fingers  can  be  flexed 
to  a  slight  degree  by  the  slips  of  the  flexor  sublimis 
attached  to  them  and  supplied  by  the  median  nerve_, 
but  flexion  of  the  terminal  phalanx  of  the  little 
finger  is  always  impossible.  Little  difficulty  should 
be  experienced  in  discovering  the  paralysis  of  the 
intrinsic  muscles  of  the  hand  supplied  by  this  nerve^ 
but  it  is  not  infrequently  overlooked.  All  true 
movement  of  abduction  and  adduction  of  the  fingers 
is  lost_,  but  a  false  abduction  can  be  carried  out  by 
the  extensor  communis  digitorum;  this  is  readily 
distinguished^  for  it  is  always  accompanied  by 
extension  of  the  basal  phalanges^  and  palpation 
reveals  the  fact  that  the  interossei  are  flaccid.  In 
palpating  the  first  interosseous  space  during  this 
movement  it  must  be  borne  in  mind  that  the  first 
lumbrical  muscle^  passing  on  the  radial  side  of  the 
index  finger  to  the  dorsal  expansion,  may  be  taking- 
part.  I  have  known  mistakes  to  occur  from  electrical 
testing  alsO;  this  muscle  reacting  to  stimulation  with 
the  interrupted  current  and  being  taken  to  be  the 
first  dorsal  interosseous.  The  adductor  muscles  of  the 
thumb  bring  this  digit  towards  the  second  metacarpal 
bone  in  a  plane  at  right  angles  to  that  of  the  palm 
(vide  Plates  XII  and  XIII).  This  movement  can  be 
well  simulated  by  means  of  the  long  flexor  and  extensor 


PLATE    XII. 


To  illustrate  true  (Plate  XII)  and  false  (Plate  XIII)  adduction  t6 
the  thuiiil).  Plate  XIII  shows  the  simulation  of  adduction  of 
the  thuiulj  in  a  jxitient  with  paralysis  of  the  adductores  pollicis. 
In  the  photograph  of  the  hand  from  the  radial  side  the  false 
adduction  is  bein*^  produced  principally  by  the  extensors,  in 
that  from  the  fi^ont,  by  the  long  flexor  muscle. 


To  face  p.  248. 


Adlard  cj-  Son,  Impr. 


PLATE    XIII. 


From  the  same  case  as  Plate  XI ^. 


To  face  p.  249. 


Adlard  S-  Son,  Impr. 


FALSE  ADDUCTIO^^  OF  THE  THUMB     249 

muscles  of  tlie  thumb  (false  adduction)  but  the 
movement  is  always  accompanied^  in  the  former  case 
by  extension  of  the  terminal  phalanx  and  outward 
rotation  of  the  thumbs  in  the  latter  by  flexion  and 
inward  rotation.  Careful  examination  will  reveal 
these  supplementary^  movements. 

Sen.^ory  symiotoms. — Epicritic  sensibility  is  lost 
over  the  little  finger  and  the  ulnar  half  of  the  ring- 
finger,  and  that  part  of  the  palm  and  dorsum  of  the 
hand  to  the  ulnar  side  of  a  line  draAvn  longitudinally 
through  the  ring  finger  and  continued  upwards. 
This  area  is  extremely  constant  and  varies  little  from 
patient  to  patient.  Its  borders  are  well  defined ;  on 
passing  from  the  median  to  the  ulnar  portion  of  the 
palm  or  in  the  reverse  direction  the  patient  can  tell 
at  once  when  the  border  is  reached,  and  the  result  of 
subsequent  stimulations  are  identical.  Protopathic 
sensibility  is  lost  over  an  area  which  varies  consider- 
ably [vide  Fig.  15)  from  patient  to  patient,  in  some 
cases  the  little  finger  and  the  extreme  ulnar  border 
of  the  palm  only  being  affected,  in  others  the  area  is 
nearly  as  large  as  that  over  which  epicritic  sensi- 
bility is  lost.  Between  the  boundaries  of  loss  of 
epicritic  and  protopathic  sensibility  is  the  inter- 
mediate zone.  Deep  sensibility  is  usually  lost  over 
an  area  almost  as  extensive  as  that  insensitive  to 
prick. 

Division  at  the  ivrist. — Accidental  division  of  the 
nerve  in   the   lower    part    of    the    forearm   is  rarely 


!50 


INJURIES    OF    NERVES 


unaccompanied   by   division    of    tendons.       In    most 
instances  the  wounds  are  due  to  broken  o'lass. 

o 

Injuries  of  tliis  type  frequently  divide  the  nerve 


Fig.  15. — Loss  of  sensiljility  produced  by  division  of  whole 
ulnar  nerve,  a  with  small,  b  with  large  exckisive  proto- 
pathic  supply. 

below  the  point  at  which  its  dorsal  branch  is  given 
off.  I  have  found  the  nerve  divided  in  this  situation 
as  often  as  the  whole  nerve.      Very  little   attention 


ULNAR    NERVE    AT    WRIST  251 

has  been  paid  to  this  form  of  injury  and  its  effects 
are  often  overlooked  on  account  of  the  slight  sensory 
symptoms  produced^  the  patient  coming  under 
observation  later,  Avitli  wasting  of  the  ulnar  muscles 
and  typical  ulnar  paralysis.  Among  the  recent  text- 
books of  surgery  and  diseases  of  the  nervous  system, 
Rose  and  Carless  and  Oppenheim  alone  draw 
attention  to  this. 

After  injury  in  both  situations  (above  and  below 
the  dorsal  branch)  all  the  intrinsic  muscles  of  the 
hand  supplied  by  the  ulnar  nerve  are  paralj^sed,  bat 
on  account  of  the  division  of  tendons  which  usually 
co-exists  this  may  be  difficult  to  elicit  immediately 
after  the  injury.  The  loss  of  sensibility  after  division 
of  the  whole  nerve  at  the  wrist  resembles  that  seen 
after  division  at  the  elbow  (Fig.  15),  with  the 
exception  that  deep  sensibility  is  usuall}''  lost  in  the 
latter  lesion  ;  in  an  uncomplicated  instance  of  division 
of  the  ulnar  at  the  wrist  it  is  usually  retained.  The 
extent  to  which  it  is  lost  depends  upon  the  division 
of  tendons ;  if  many  are  divided,  deep  touch  may 
be  lost  over  an  area  as  extensive  as  that  of  the 
protopathic  loss  ;  when  no  tendons  are  divided,  it  is 
lost  over  the  terminal  phalanges  of  the  little  finger 
at  most. 

After  division  of  the  nerve  below  the  point  at 
which  its  dorsal  branch  is  given  olf  epicritic  sensi- 
bility is  lost  over  an  area  on  the  palm  [vide  Fig.  16) 
corresponding  exactly  to  that  which  is  affected  after 


252 


INJURIES    OF    NERVES 


section  of  the  whole  nerve.  Its  palmar  boundary  is 
definite,  but  at  the  ulnar  border  it  gradually  merges 
into  the  normal  sensibility  of  the  dorsum  of  the 
hand ;  there  is  no  well-defined  boundary  here 
between  sensitive  and  insensitive  parts.  On  the 
dorsum  the  terminal  two  phalanges  of  the  little  and 
half  of  the  terminal  two  phalanges  of  the  ring- 
fingers  usually  become  insensitive  to  these    stimuli. 


Fig.  16. — To  illustrate  the  loss  of  sensibility  produced  by 
division  of  tlie  nlnar  nerve  below  its  dorsal  branch. 


Deep  sensibility  is  everywhere  retained.  The  extent 
of  protopathic  loss  varies  within  wide  limits  ;  usually 
the  terminal  phalanx  of  the  little  finger  only  is 
insensitive,  but  an  area  almost  as  large  as  that  of  the 
loss  of  sensibility  to  light  touch  may  be  present. 
This  area  of  protopathic  loss  may  vary  in  extent 
from  time  to  time  in  the  same  patient.  In  a  patient 
in  whom,  at  the  operation,  I  discovered  that  the 
ends  of  the  nerve    had    been  united  to  tendons,  the 


FULL  SUPPLY  OF  ULNAE,  NERYE     253 

extent  of  tlie  insensibitity  to  prick  had  varied  from 
a  small  area  on  tlie  j^alm  to  one  almost  corresponding 
to  that  of  the  loss  of  sensibility  to  touch.  The  same 
phenomenon  may  occur  after  division  of  the  external 
popliteal  nerve  below  its  lateral  cutaneous  branch 
{vide  p.  299). 

F'ldl   sufijly    of   tlie   ulnar  nerve. — As    mentioned 
previously^  division  of  a  nerve  depicts  only  the   area 


Fig.  17. — To  illustrate  the  full  protopatliic  supi^ly  of  the 
ulnar  nerve. 


exclusively  supplied  by  it.  Its  full  supply  can  only 
be  obtained  from  patients  in  whom  surrounding- 
nerves  have  been  divided^  leaving  intact  the  area 
supplied  by  the  nerve  we  wish  to  study.  Knowledge 
of  the  full  supply,  especially  of  the  nerves  of  the 
hand,  is  necessary  in  the  diagnosis  of  irritative 
lesions. 

Fig.  17,  showing    the   full    protopatliic   supply   of 
the    ulnar    nerve,    was   taken    from   a    patient    who 


254  INJURIES    OF    NERVES 

divided  all  the  cutaneous  nerves  of  tlie  hand  except 
the  ulnar^  and  corresponds  exactly  to  the  area  which 
became  tender  in  patients  with  incomplete  division 
of  the  ulnar  nerve  and  irritation.  It  must  be 
remembered^  however_,  that  as  the  exclusive  area 
supplied  with  protopathic  sensibility  from  any  one 
nerve  varies^  so  the  full  supply  must  vary. 

The  full  epicritic  supply  corresponds  practically  to 
its  exclusive.  The  overlap  in  the  nerves  carrying 
epicritic  stimuli  is  negligible. 

Treatment. — Special  care  must  be  taken  in  all 
ulnar  injuries  to  prevent  the  deformity  from  be- 
coming permanent.  A  splint  must  be  worn,  at  least 
during'  the  night  time,  until  the  muscles  regain  their 
power  of  voluntary  movement.  If  this  is  not  done 
the  interossei  muscles  become  stretched  and  changes 
take  place  in  the  ligaments  of  the  inter-phalangeal 
joints,  rendering  the  recovery  of  perfect  function  im- 
possible, although  regeneration  of  the  nerve  may  take 
place  and  the.  muscles  regain  their  irritability  to  the 
interrupted  current.  It  is  also  necessary  to  institute 
exercises  as  soon  as  voluntary  power  begins  to 
return. 

Prognosis  and  method  of  recovery. — After  com- 
plete division  of  the  ulnar  nerve  in  any  part  of  its 
course  followed  by  primary  suture,  the  first  sign  of 
restoration  of  sensibility  to  prick  will  be  noticed  in 
from  six  weeks  to  three  months  if  the  wound  heal  by 
first  intention,  and   will   be   completely    restored    in 


ULXAPt    NERVE  255 

about  five  moiitlis  after  division  at  the  wrists  but  a 
longer  time  will  be  necessary  for  the  completion  of 
the  first  stage  when  divided  at  a  higher  level.  After 
division  at  the  wrist^  sensibility  to  light  touch  com- 
mences to  return  in  about  six  months,  and  should  every- 
where be  ajDpreciated  in  about  ten.  If  divided  in 
the  forearm  or  higher  a  much  longer  time  is 
necessary  for  the  commencement  and  completion  of 
the  restoration  of  sensibility  to  light  touch.  But  as 
I  have  already  poinfed  out,  complete  sensory  re- 
covery takes  a  much  longer  time.  In  cases  of 
primary  suture,  uncomplicated  by  sepsis,  it  will 
certainly  occur  if  the  after-treatment  is  efficient,  but 
will  take,  in  all  probability,  about  two  years. 

After  secondary  suture  complete  sensory  recovery 
is  improbable,  and  it  is  unlikely  that  the  hand  will 
ever  completely  regain  its  former  usefulness. 

Motor  recovery  will  take  ^^lace  in  all  cases  in 
which  there  is  no  septic  complication,  but  at  a  time 
varying  with  the  level  of  the  lesion.  When  the 
nerve  is  divided  at  the  wrist,  the  first  sign  of  volun- 
tary power  and  excitability  to  the  interrupted 
current  will  be  noticed  in  about  eleven  months. 
After  suture  at  the  elbow,  more  than  two  years  will 
elapse  before  voluntary  power  is  regained  in  the 
muscles  of  the  hand.  In  cases  of  secondary  suture 
in  which  the  ulnar  position  of  the  hand  is  marked 
before  operation,  complete  motor  recovery  is  ex- 
tremely unlikely.      Voluntary  power  will   return   to 


256  INJUEIES    OF    NERVES 

tlie  paralysed  muscles,  but  these  may  remain 
atropine  if  tlie  normal  position  of  tlie  fingers  cannot 
be  restored.  Careful  examination  sliould  be  made^, 
and  tlie  patient  informed  before  operation  is  under- 
taken of  the  amount  of  success  expected. 

Injmies  of  the  ulnar  nerve  in  fractures,  recent  and 

remote Injuries     of     the     ulnar     nerve    in   recent 

fractures  or  dislocations,  either  as  a  primary  or 
secondary  affection,  are  not  uncommon,  coming  next 
in  frequency  in  the  upper  limb  to  injuries  of  the 
musculo- spiral  nerve  in  fractures  of  the  humerus. 
Bruns  records  that  in  188  cases  of  nerve  injuries 
complicating  fractures  19  were  ulnar. 

The  injury  occurs  in  fractures  involving  the 
internal  condyle  and  the  division  is  usually  physio- 
logical and  incomplete.  Involvement  of  the  ulnar 
nerve  in  a  I'ecent  fracture  or  epiphysial  separation 
of  the  lower  end  of  the  humerus  is  an  additional 
indication  for  operation  in  these  cases.  In  disloca- 
tions the  usual  treatment  for  incomplete  division 
should  be  carried  out. 

Interference  with  the  functions  of  the  ulnar  nerve 
arising  many  years  after  an  injury  in  the  region  of 
the  elbow  which  has  led  to  permanent  deformity 
is  not  so  well  recognised,  and  has  often  led  to 
errors  in  diagnosis.  Attention  was  first  directed  to 
this  subject  in  1877  by  Panas.  He  recorded  three 
cases  of  this  nature,  and  stated  that  the  condition 
had  led  to  errors  in  diagnosis,   and    that   Duchenne 


ULNAR  XERVE  :  INJURY  IN  FRACTURES  257 

had  at  first  mistaken  sucli  a  case,  with  other  eminent 
physicians^  fur  disease  of  the  spinal  cord^  but  by 
careful  attention  to  details  he  had  been  able  to 
rectify  the  error.  Similar  mistakes  are  still  being* 
made. 

I  have  been  able  to  tind  record  of  seventeen  cases 
of  late  involvement  of  the  ulnar  nerve  after  fractures 
of  the  lower  end  of  the  humerus^  and  have  had  five 
under  my  care,  upon  two  of  whom  I  operated. 

The  injury  producing  the  deformity  has  been,  in 
most  cases,  a  fracture  or  epiphysial  separation  of  the 
lower  end  of  the  humerus  Avliich  has  led  to  a  marked 
cubitus  valgus,  often  with  obliteration  of  the  ulnar 
groove  behind  the  internal  condyle. 

The  symptoms  appear  usually  many  years  after 
the  injury.  In  most  of  the  recorded  instances  the 
accident  was  in  childhood,  and  in  several  cases  no 
history  of  the  injury  could  be  obtained.  This  Avas  the 
case  in  one  of  the  patients  upon  Avhoni  I  operated, 
but  the  physical  signs  and  the  radiograph  left  no 
doubt  as  to  the  origin  of  the  marked  cubitus  valgus 
which  was  present. 

The  first  symptom  noticed  is  generally  pain  in  the 
distribution  of  the  nerve  ;  this  is  soon  folloAved  by 
wastino-  and  weakness  in  the  muscles  which  it 
supplies.  This  may  have  gone  on  to  complete 
division,  but  as  a  rule  the  signs  are  those  of  incom- 
plete division  only.  The  patient  may  be  unaware  of 
any  deformity  at  the  elbow,  and  it  is  only  on  tracing 

17 


258  INJURIES    OF    NERVES 

the  nerve  upwards  in  tlie  usual  way  that  the  nature 
of  the  case  is  discovered ;  but  this  is  unusuaL 

The  uhiar  nerve  is  enlarged  into  a'  spindle-shaped 
swelling  behind  the  internal  condyle.  This  was  well 
marked  in  the  patients  upon  whom  I  operated ;  the 
enlargement  was  smooth  and  quite  free  from 
adhesions  to  surrounding  p^rts. 

The  period  between  the  injury  and  the  onset  of 
symptoms  varies.  The  longest  of  which  I  have  note 
is  twenty-seven  years.  In  some  instances  it  seems  that 
excessive  work  or  a  change  of  occupation  has  pre- 
ceded the  onset  of  symptoms  ;  in  most  of  the  patients 
no  such  history  was  obtainable. 

I  have  had  the  opportunity  of  carefully  examining 
the  portion  of  nerve  removed  from  one  patient.  The 
pathological  change  was  strictly  limited  to  the  spindle- 
shaped  swelling.  The  nerve  immediately  above  was 
perfectly  healthy ;  that  below  showed  degenerated 
fibres  with  a  few  small  healthy  medullated  fibres,  the 
degenerated  being  in  the  usual  ^^  resting  ^^  condition. 
At  the  seat  of  the  injury  was  a  mass  of  cellular 
fibrous  tissue  in  which  it  was  almost  impossible  to 
trace  any  nervous  structure.  These  appearances 
agree  with  the  only  similar  examination  published, 
that  of  Panas,  who  was  able  to  obtain  the  specimen 
after  death  of  the  patient  from  pyyomia.  The  cause 
is  a  local  interstitial  neuritis,  due  to  repeated 
friction  or  pressure  upon  the  nerve,  symptoms  only 
appearing    when    the    fibrous    tissue    has   increased 


ULNAR  NP]RVE  :  IXJURY  IN  FRACTURES   259 

sufficiently  to  press  upon  tlie  axis  cylinders,  and  will, 
if  not  treated,  progress  to  complete  physiological 
division. 

Diagnosis. — If  the  existence  of  this  condition  is 
remembered  no  difficulty  should  arise.  Disloca- 
tion of  the  ulnar  nerve  may  be  suspected  but 
the  absence  of  undue  mobility  and  the  gradual 
onset  of  symptoms  renders  diferential  diagnosis 
easy.  In  many  of  the  cases  the  diagnosis  of  anterior 
poliomyelitis  was  made.  Careful  attention  to  the 
symptoms  wdll  prevent  this  mistake.  The  typical 
deformity  in  the  region  of  the  elbow  and  the  spindle- 
shaped  swelling  upon  the  nerve  establishes  the 
diao-nosis.  The  descree  of  involvement  must  then  be 
settled;   in  most  cases  the  division  is  incomj^lete. 

Treatment. — In  all  cases  means  should  be  taken 
to  remove  the  cause  of  the  disease.  In  the  least 
severe  cases,  rest  will  entirely  relieve  the  symptoms 
for  a  time,  but  recurrence  inevitably  takes  place  on 
resumino'  active  use  of  the  forearm. 

The  nerve  should  be  exposed  behind  the  internal 
condyle  and  a  groove  in  the  bone  chiselled  for  it ; 
if  the  cubitus  valgus  is  excessive  it  maybe  necessary 
to  remedy  this.  When  the  signs  are  those  of 
incomplete  division  only,  removing  the  cause  of  tlie 
pressure  and  protecting  the  nerve  will  be  sufficient, 
but  when  the  signs  arc  those  of  complete  division, 
the  spindle-shaped  swelling  should  be  excised  and 
end-to-end  suture  performed  in  addition. 


260  INJURIES    OF    NERVES 

Dislocation  of  the  ulnar  nerve. —Abnormal  mobility 
of  tlie  ulnar  nerve  ia  common  and  gives  rise  to  no 
symptoms.  Hain^  who  is  confirmed  by  Colin,  found 
it  in  25  per  cent,  of  men,  13  per  cent,  of 
women.  It  occurs  in  tliose  individuals  in  whom  the 
physiological  cubitus  valgus  is  more  marked  than 
normal.  It  may  also  a.rise  in  traumatic  cubitus 
valgus.  This  abnormal  mobility,  to  which  the  name 
"  subluxation  "  is  given,  is  the  predisposing  cause  of 
dislocation,  the  term  "  dislocation  '^  being  confined  to 
those  cases  in  which  the  nerve  passes  forwards  over 
the  internal  condyle. 

Traumatic  dislocation  of  the  ulnar  nerve  can  only 
occur  in  flexion  of  the  elbow.  During  this  move- 
ment the  nerve  has  a  tendency  to  pass  inwards  like 
the  string  of  a  bow ;  this  tendency  is  increased  in 
cubitus  valgus.  A  fall  on  the  flexed  elbow  is  given 
as  the  cause  of  this  accident  in  many  cases,  sudden 
and  violent  flexion  rupturing  the  fibres  of  the  fascia 
Avhich  keep  it  in  position. 

The  symptoms  are  commonly  met  with  in  males 
between  the  ages  of  twenty  and  thirty.  Suddenly, 
after  an  injury  to  the  elbow,  pain  is  felt  in  the 
distribution  of  the  ulnar  nerve,  usually  accompanied 
by  alteration  in  sensibility  and  weakness  of  muscles. 
Symptoms  are  relieved  by  rest  and  recur  with 
frequency  on  resuming  use  of  the  arm  ;  the  repeated 
insults  to  which  the  nerve  is  subject  in  passing  over 
the    internal    condyle    may   lead    to    an    interstitial 


DTSLOCATIOX    OF    ULNAR    NERVE        261 

neuritis,  and  the  formation  of  a  spinclle-sliapecl 
swelling  on  the  nerve  with  a  gradual  deterioration 
of  function  up  to  complete  division.  Occasionally 
the  dislocation  arises  without  sudden  injury  (these 
are  the  so-called  congenital  cases);  it  is  probable  that 
here  the  fascia  keeping  the  nerve  in  position  becomes 
gradually  stretched,  and  at  last  allows  the  nerve  to 
pass  over  the  condyle. 

Treatment. — Operation  is  necessary  if  symptoms 
are  present  pointing  to  interference  with  the  functions 
of  the  nerve.  A  long  incision  should  be  made 
behind  the  internal  condyle  to  expose  the  nerve ; 
after  freeing  the  nerve,  the  groove  in  the  bone 
should  be  deepened,  if  necessary,  and  the  nerve 
wrapped  in  membrane  to  jDrevent  it  from  forming- 
adhesions,  and  finally  the  bony  groove  converted 
into  a  canal  by  stitching  a  portion  of  the  fascia  of 
the  triceps  over  it.  In  neglected  cases  in  which  a 
spindle-shaped  swelling  is  found  on  the  nerve  and 
the  signs  of  complete  division  are  present,  it  will 
be  necessary  to  resect  the  damaged  portion ;  this, 
however,  is  rarely  required. 

Examination  and  diagnosis. — The  complete  routine 
examination  is  necessary  in  order  to  form  a  correct 
and  complete  diagnosis.  In  patients  in  whom 
symptoms  of  involvement  of  the  muscles  of  the  hand 
supplied  by  the  ulnar  nerve,  or  of  alteration  in 
sensibility  or  pain  in  the  ulnar  area  are  present, 
especially  when  no  history  of  iujury  can  be  obtained. 


262  INJURIES    OF    NERVES 

some   difficulty  ma}"  be    experienced.      A    lesion    of 
tlie  ulnar  nerve  lias  to  be  diagnosed  from  one  of  tlie 
first  dorsal  root  or  of  the  inner  cord  of  the  plexus. 
In  both  these  cases   all  the  intrinsic  muscles  of  the 
hand  are  affected  and  the  hand  assumes    the    true 
claw  shape ;  all  the  fingers  are  equally  hyperextended 
at  the  metacarpo-phalangeal  and  flexed  at  the  inter- 
phalangeal  joints.      In   lesions   of   the    ulnar   nerve 
this  is  not  the  case  :  the  hyper-extension  and  flexion 
is  most  marked  in  the  little  and  ring  fingers,  least 
in  the  middle  and  index,  these  fingers  being  kept  at 
their  metacarpo-phalangeal  joints  and  slightly  flexed 
at  their  interphalangeal.    In  lesions  of  the  inner  cord 
the   muscles   supplied   by   the    ulnar    nerve   in    the 
forearm  are  affected  in  addition. 

The  loss  of  sensibility  even  in  complete  lesions  of 
the  first  dorsal  root  is,  as  a  rule,  ill-defined,  and 
partakes  of  the  character  laid  down  on  p.  24  as 
characteristic  of  root  lesions.  The  cervical  sym- 
pathetic may  also  be  affected.  In  inner  cord  lesions 
sensory  symptoms  will  be  present  in  proportion  to 
the  muscular  changes,  and  affect  the  forearm  as  well 
as  the  ulnar  area  on  the  hand. 

The  median  nerve. — This  nerve  resembles  the  ulnar 
in  being  most  frequently  injured  through  wounds  in 
the  region  of  the  wrist  made  by  broken  glass;  it 
may  also  be  wounded  in  incised  wounds  in  other 
parts  of  its  course,  involved  in  fractures  of  the  lower 
end  of  the  humerus  or  radius,  or  in  fractures  of  both 


MEDIAN    NEEVE  263 

bones  of  the  forearm  (in  this  last  variety  of  fracture 
its  anterior  interosseous  branch  may  be  injured 
alone).  It  also  not  infrequently  suffers  as  the  result 
of  splint  pressure,  and  may  be  affected  in  various 
occupations,  cigarette-makers,  carpenters  and  pro- 
fessional golfers. 

In  connexion  with  injury  at  the  wrist  it  should  be 
remembered  that  the  nerve  is  here  subcutaneous, 
lying  between  the  tendons  of  the  flexor  carpi  radialis 
and  palmaris  longus  and  outermost  tendon  of  the 
flexor  sublimis  digitorum.  It  may  be  injured  in  this 
situation  through  a  small  punctured  wound  which 
divides  no  other  subcutaneous  structure.  Division 
of  the  median  nerve  without  division  of  tendons  is 
common,  division  of  the  ulnar  nerve  without  division 
of  tendons  rare. 

Sensory  symijtoms. — If  the  median  nerve  is  divided 
at  the  Avrist,  deep  touch  can  be  appreciated  over  the 
whole  of  the  affected  area.  It  is  important  to 
recognise  this ;  for  division  of  the  median  is  more 
often  overlooked  than  division  of  all  other  nerves  put 
together  chiefly  for  this  reasou. 

Sensibility  to  light  touch  is  lost  over  an  area  on 
the  palm  [ridp  Fig.  18),  bounded  by  a  line  running 
through  the  axis  of  the  ring  flnger.  At  the  thenar 
eminence  the  boundary  curves  radialwards  and  then 
runs  to  the  radial  edge  of  the  thumb-nail.  Starting 
again  at  the  ulnar  border  of  the  nail,  it  passes  along 
the   free    border   of  the  first  interosseous  space  and 


264 


INJURIES    OF    NERVES 


tnrnR  downwards  opposite  the  highest  fold  over  the 
first  inter-phalangeal  joint.  On  the  dorsum  the  last 
two  and  a  half  phalanges  of  the  middle  and  index 
and    half    of   the   last  two    of   the    ring    finger   are 


Fig.  18. — Loss  of  sensibility  produced  by  division  of  the 
whole  median,  a  with  small,  b  with  large  exclusive  proto- 
pathic  supply. 

insensitive  to  epicritic  stimuli.  I  ha.vc  not  observed 
anaesthesia  of  the  dorsal  surface  of  the  phalanges  of 
the  thumb  as  figured  in  many  text-books^  although  I 
have   carefully  examined  forty-one  cases  of  median 


MEDIAN  XERYE  SENSORY  SY:\[PT0MS    2G5 

injury.      In  all  uncomplicated  cases  of  division  of  the 
median  nerve  tlie  patient  was  able  to  appreciate  all 
stimuli  applied  to  the  dorsal  surface  of  the  thumb. 
The  line  bounding  the  loss  of  epicritic  sensibility  is 
well  defined,  the  line  of  transition  from  aesthetic  to 
anaesthetic    portions    is   abrupt.       This   area    of   loss 
varies  within  verj^  slight  limits  only  ;  on  no  occasion 
have   I   seen    the   ring  finger  unaffected.      But  it  is 
otherwise  with  the  loss  of  sensibility  to  prick.     This 
varies  within  Avide  limits  :    it  may  include  not  quite 
the  whole  of  the  terminal  two  phalanges  of  index  and 
middle  fingers  (Fig.  18a),  or  be  almost  as  widespread 
as  the  loss  of  sensibilit}^  to  light  touch   (Fig.  18  b). 
In  the  patients  from  whom  these  figures  Avere  taken 
the   nerve    Avas   di Abided   at    the   AA^rist,   in  Fig.    18  b, 
through  a  small  punctured  Avound  Avhich  di Added  no 
other  structure.      In  one  instance  of  division  of  the 
nerve  at  the  elboAV  the  loss  resembled  that   seen   in 
the    latter   figure.       After   division    of    the    median 
nerve,   hoAA^CA^er,   at   whatever  IcA'el   it   occurs,   it   is 
more  usual  for  protopathic  stimuli  to  be  appreciated 
OA'er    the    palm,  and   for  the   loss    of   this   form   of 
sensibility  to  resemble  that  seen  in  Fig.  18  a. 

In  many  of  the  injuries  in  the  neighbourhood  of 
the  Avrist,  tendons  are  diAaded  in  addition ;  this 
usually  results  in  the  appearance  of  an  area  insen- 
sitiA^e  to  deep  touch  almost  as  extensiA^e  as  that  of 
the  loss  of  sensibility  to  prick.  In  the  patient  from 
Avhom  Fig.    18  a  Avas  taken,  the  nerA^e   Avas    diA^ded 


266 


INJURIES    OF    NERYES 


through  an  extensive  wound  at  the  wi^ist  and  many 
tendons  were  also  severed  ;  the  area  of  loss  of  deep 
sensibility  corresponded  to  the  area  insensitive  to  the 
point  of  a  pin.  Deep  sensibility  was  present  every- 
where in  the  patient  from  whom  Fig.  18  b  was 
taken,  although  the  area  of  insensibility  to  prick  was 
so  much  greater. 

Thus_,  after    division  of  the  median  nerve  at  the 
wrist   there    may   be   no    portion    of  the   hand  over 


Fig.   19. — Illustrating  the  full  protopatliic  supply  of  the 
median  nerve. 

which  the  patient  cannot  distinguish  all  stimuli 
usually  called  tactile,  and  an  area  of  considerable 
size  may  be  present  on  the  palm,  within  which  the 
patient  appreciates  the  point  of  a  pin  as  a  diffuse 
painful  stimulus,  and  can  distinguish  between  ice 
and  water  at  50'^  C. 

Division  of  the  nerve  at  the  oIIjow  or  even  in  the 
axilla  does  not  increase  the  extent  of  the  loss  of 
epicritic  or  protopatliic  sensibility,  but  usua]ly  affects 
deep  sensibility. 


MEDTAX     XET7YE:     MOTOK     SY:\n^TO:\[S    207 

So  far  the  exclusive  supply  only  of  the  nerve  has 
been  dealt  with.  Looked  at  from  the  standpoint  of 
residual  sensibility  it  will  be  seen  that  there  can  be 
very  little  overlap  in  the  fibres  subserving  sensibility 
to  light  touch ;  its  exclusive  and  full  supplies  are, 
therefore,  identical.  But  it  is  otherwise  watli  proto- 
pathic  sensibility ;  the  full  suppl}^  i^^^y  bear  very 
little  relation  to  the  exclusive.  Fig.  19,  repre- 
senting the  full  area  supplied  by  the  nerve  with 
protopathic  fibres,  was  obtained  from  patients  in 
whom  the  ulnar,  radial  and  external  cutaneous 
nerves  were  divided.  But  it  is  to  be  remembered 
that  it  will  vary  somewhat  from  patient  to  patient. 
It  corresponds  closely  to  the  area  w^hicli  becomes 
tender  on  stimulation  of  the  nerve. 

Motor  f<ymiJtoms. — After  division  at  the  elbow^  the 
patient  may  experience  little  discomfort  from  the 
paralysis  ;  the  impairment  of  mobility  affects  chiefly 
the  thumb,  and,  to  a  less  extent,  the  index  finger. 
The  terminal  phalanx  of  the  thumb  cannot  be  flexed 
owang  to  the  paralysis  of  the  flexor  longus  pollicis 
(this  is  a  most  important  symptom) ;  the  index  finger 
can  only  be  flexed  at  its  metacarpo-phalangeal  joint 
by  means  of  the  interossei  muscles  attached  to  it, 
both  long  muscles  being  dependent  on  the  median 
for  their  supply.  Pronation  of  the  forearm  is  feeble, 
and  only  possible  by  the  weight  of  the  arm.  The 
principal  test  of  division  of  the  median  nerve  above 
the  point  at  which  its  motor  branches  to  the  forearm 


268  IXJURIER    OF    X REYES 

muscles  are  given  off^  is  paralysis  of  tlie  flexor 
longns  pollicis  muscle.  It  must  be  remembered  that 
these  branches  are  given  off  just  below  the  elbow, 
consequently  division  in  the  upper  third  of  the 
forearm  may  leave  them  unaffected. 

After  division  at  the  wrist  the  abductor-opponens 
group  of  muscles  and  the  outer  two  lumbricales  only 
are  affected.  It  is  essential  to  understand  the  action 
of  the  abductor  and  opponens.  The  abductor  pollicis 
takes  the  thumb  away  from  the  index  finger  in  a 
plane  at  right  angles  to  that  of  the  palm — an  action 
that  is  not  one  of  the  ordinary  movements  of  d-aily 
life  ;  this  is  the  action  which  is  lost  and  which  can 
be  only  feebly  imitated  by  the  extensor  brevis  and 
ossis  metacarpi  pollicis  {vide  Plates  XIY,  XY).  In 
testing  the  action  of  the  abductor  pollicis  the 
patient  should  be  asked  to  touch  a  pencil,  or  the 
observer's  finger  held  immediately  in  front  of  the 
thumb,  the  hand  being  placed  with  its  dorsum  on 
the  table. 

In  opposition  the  thumb  is  rotated  so  that  its 
palmar  surface  looks  towards  the  palm  (Plate  XYI  a)  ; 
for  the  perfect  performance  of  this  movement  the 
action  of  the  opponens  pollicis  is  necessarj^,  but  it  is 
often  difficult  to  tell  from  inspection  alone  that  the 
movement  is  being  produced  by  the  long  flexor  of 
the  thumb  and  the  abductor  muscles  (Plate  XYI  b). 
Palpation  over  the  insertion  of  the  opponens  to  the 
metacarpal   bone    of    the    thumb   may  be    necessary 


PLATE    XIY. 


w 

^ 

To  illustrate  (a)  true  abduction  of  the  thumb,  (b)  false  abduction 
of  the  thumb  ;  seen  from  the  pahuar  surface. 


To  face  p.  268. 


Adlard  S'  Son,  Imyr. 


PLATE    XY. 


To  illustrate  (a)  true,  (b)  false  abduction  of  the  thumb;  viewed 
from  the  radial  side. 


To  face  p.  268. 


Adlai'd  S'  Son,  Impr. 


PLATE   XYI. 


Showing  true  (a)  and  false  (b)  opposition  of  the  thumb. 
To  face  p.  269.  Adlard  Jjr  Son,  Impr. 


MEDIAN    NERVE:    DIAGNOSIS  269 

before   coming   tu    any    decision    ^vitli    regard  to    its 
paralysis. 

The  action  of  the  superficial  head  of  the  flexor 
brevis  pollicis  cannot  be  separated  from  that  of  the 
abductor,  and  the  paralysis  of  the  outer  two  lumbri- 
cales  produce  no  symptoms  that  can  be  recognised. 

The  branch  supplying  the  abductor  -  opponens 
group  of  muscles  may  be  given  off  in  the  lower 
third  of  the  forearm  instead  of  its  usual  position 
immediately  beloAv  the  annular  ligament^  and  so 
escape  injury  in  division  of  the  median  at  wrist.  I 
have  recorded  such  an  abnormality.  In  a  patient 
upon  whom  I  performed  primary  suture  at  the 
wrist  I  could  discover  no  paralysis  of  the  muscles 
of  the  thumb  before  operation.  At  the  operation  I 
found  that  the  branch  supplying  these  muscles  was 
given  off  in  the  low^cr  third  of  the  forearm  and  had 
escaped  injury. 

Diagnosis. — Injury  to  the  median  nerve  is  still 
frequently  overlooked  owing  to  the  retention  of  deep 
sensibility^  the  relatively  small  loss  of  protopathic 
sensibility  in  many  cases,  and  the  absence  of  any 
characteristic  attitude  such  as  is  seen  after  injury  to 
the  ulnar  or  musculo-spiral,  and  the  relatively  slight 
paralysis  resulting  from  its  complete  division.  I 
have  seen  complete  division  of  this  nerve  over- 
looked by  all  the  members  of  a  post-graduate  class 
in  surger}'. 

The   effect  of    the  division   of    the   median   nerve 


270  INJURIES    OF    NERVES 

upon  motion  and  sensation  lias  given  rise  to  much 
controversy,  and  liad  much  to  do  with  the  establish- 
ment and  perpetuation  of  the  error  with  regard  to 
primary  union  {vide  p.  100). 

It  is  only  by  carefully  examining  in  a  routine 
manner  all  injuries  in  the  region  of  the  wrist  that 
the  diasrnosis  will  be  made.  It  is  a  serious 
thing  for  the  patient  to  have  a  complete  division  of 
this  nerve  missed ;  the  probability  is  that  sensibility 
will  never  become  perfect  after  secondary  suture  ;  it 
will  certainly  become  so  in  an  uncomplicated  case  of 
primary  suture  of  this  nerve  in  which  the  after- 
treatment  is  faithfully  carried  out. 

Recovery  and  prognosis. — Recovery  follows  the 
usual  lines.  After  suture  the  first  sign  of  restora- 
tion of  sensibility  to  prick  is  noticed  in  from  six 
weeks  to  three  months.  Light  touch  may  be 
expected  to  commence  to  return  after  suture  at  the 
wrist  in  about  nine  months,  and  to  be  completely 
restored  in  about  twelve  months.  When  divided 
nearer  the  centre  a  correspondingly  longer  time  is 
necessary.  Complete  sensory  recovery  follows  the 
same  course  as  after  division  of  other  nerves. 

After  suture  at  the  wrist  a  return  of  power  in 
the  paralysed  muscles  may  be  expected  in  about  ten 
months. 

The  prognosis  after  division  of  this  nerve  is  good, 
better  than  after  a  similar  injury  to  the  ulnar ;  the 
muscular  recovery  is  not  liable   to  be  hindered   by 


MEDIAN    AND    ULNAR    NERVES       271 


deformity,  hence  it  is  more  often  perfect,  even  it'  no 
after-treatment  is  carried  out. 

Median  and  ulnar  nerves. — These  nerves  are  not 
infrequently  injured  simultaneously,  most  often  in 
accidentally-inflicted  wounds  in  the  region  of  the 
wrist,  then  as  the  result  of  tight  splints  in  the  treat- 
ment of  fractures  of  the  forearm ;  interference  Avith 
the  functions  of    these    nerves    is    present   in    many 


Fig.  20. — Illiistratinj^  the  loss  of  sensibility  rcsiillinj^  from 
complete  anatomical  division  of  ulnar,  incomplete 
anatomical  division  of  median  nerve. 

cases  of  Volkmann^s  ischa^mic  contracture  of  the 
forearm  muscles.  They  are  occasionally  involved  in 
fractures  or  epiphysial  separations  of  the  lower  end 
of  the  humerus  or  in  fractures  of  the  forearm. 

When  resulting  from  wounds  in  the  region  of  the 
wrist  the  division  of  the  median  is  not  uncommonly 
incomplete ;  a  not  infrequent  accident  is — complete 
anatomical  division  of  the  ulnar  nerve  accompanied  by 
incomplete  anatomical  division  of  the  median.  Fig.  20 
represents  the  loss  of  sensibility  to  be  expected  in  cases 


272  INJURIES    OF    NERVES 

of  tliis  nature.  The  injury  to  the  median  is  usually  suffi- 
cient to  paralyse  for  a  time  the  intrinsic  muscles  of  the 
hand  which  it  supplies_,  and  they  often  develop  the 
reactions  typical  of  incomplete  division  and  demon- 
strate them  well  in  comparison  to  the  true  reaction 
of  degeneration  in  the  muscles  supplied  by  the  com- 
pletely divided  ulnar  nerve. 

When  both  nerves  are  completely  divided  (Fig.  21) 
the  area  insensitive  to  light  touch  occupies  the  whole 
of  the  palm  and   palmar  surface  of  the   thumb   and 
fingers.      Its  boundary  towards  the  radial  side  is  that 
seen   after   division    of   the   median   nerve.      On  the 
dorsal   as  on  the    palmar   surface   the   loss   of  light 
touch  corresponds   exactly  to  that  produced  by  divi- 
sion of   the   ulnar   nerve   added   to    that   caused   by 
division    of    the    median.      The   loss   of    protopathic 
sensibility  varies  with  the  extent  to  which  the  radial 
portion  of   the   palm   is   supplied   with   this   form  of 
sensibility   from    the   radial   and   external   cutaneous 
nerves.      Usually    the    loss    of    sensibility    to    prick 
extends  from  the  ulnar  side  to  the  cleft  between  the 
index  and  middle  fingers  ;  the  palmar  surface  of  all 
the  fingers   is  affected.      On  the  dorsal  surface    the 
area  insensitive  to  these  stimuli   does  not  differ  from 
the  sum  of  that  which   results  from  division  of  the 
nerves   separately.       In    those    cases    in    which    the 
median  nerve    supplies  a  large  portion  of  the  radial 
half  of  the  palm  and  palmar  surface  of  the  thumb 
the   loss   is    correspondingly   greater.       Fig.  21  also 


MEDIAN    AND    ULXAK    NEKYES       273 


gives  the  full  supply  of  the  radial  and  external  cuta- 
neous nerves  on  the  palm  of  the  hand. 

After  the  usual  accidental  division  of  the  median 
and  ulnar  nerves  with  many  tendons,  deep  sensibility 
is  abolished  over  an  area  almost  as  extensive  as  that 
which  becomes  insensitive  to  prick.  To  ascertain 
the  extent  of  insensibility  to  deep  touch  from  division 
of  these  nerves  alone  a  case  uncomplicated  by  division 


Fig.  21. — Showing  the  loss  of  sensibility  resulting  from  com- 
plete division  of  the  median  and  ulnar  nerves. 

of  tendons  must  be  investigated.  It  is  rarely  this 
opportunity  occurs  as  the  result  of  accidental 
section_,  but  in  a  patient  upon  whom  secondary  suture 
was  performed  six  months  after  the  injury,  the 
tendons  had  been  united  at  the  time  of  the  accident. 
Immediately  after  the  operation  of  secondary  suture 
he  could  appreciate  and  localise  deep  touch  correctly 
over  the  whole  area  insensitive  to  prick^  with  the 
exception  of  the  palmar  surface  of  the  little  finger 
and  the  greater  part  of  the  dorsum — an  area  which 

18 


274  ^JURIES    OF    NERVES 

becomes  insensitive  in  many  cases  after  division  of 
the  ulnar  nerve  alone. 

Tlie  ulnar  nerve  is  sometimes  divided  below  its 
dorsal  branch  with  a  corresponding  smaller  loss  of 
sensibility. 

After  division  of  the  median  and  ulnar  nerves  the 
hand  assumes  the  true  claw  shape^  with  all  the 
fingers  hyper-extended  at  the  metacarpo-phalangeal 
and  flexed  at  the  interphalangeal  joints ;  after  divi- 
sion above  the  point  at  which  the  forearm  muscles 
are  supplied  the  wrist  tends  to  become  hyper- 
extended,  and  all  the  flexor  muscles  of  wrist  and 
fino-ers  are  paralysed.  All  the  intrinsic  muscles  of 
the  hand  are  paralysed  and  the  only  movements  that 
can  be  performed  are  those  of  the  long  muscles.  No 
difficulty  should  arise  in  diagnosis  after  division  in 
any  situation. 

Method  of  recovery. — Restoration  of  sensibility  to 
prick  is  first  noticed  in  the  median  area  of  the  palm, 
and  its  complete  restoration  occupies  about  the  same 
time  as  when  the  ulnar  alone  is  divided  at  the  Avrist.  It 
seems  probable  that  the  restoration  of  epicritic  sensi- 
bility requires  a  longer  time  than  after  division  of 
one  nerve  alone. 

The  abductor-opponens  group  always  regain 
voluntary  power  and  excitability  to  the  interrupted 
current  before  the  muscles  supplied  by  the  ulnar 
nerve. 

Division  of  the  median   and   ulnar   nerves   is   an 


MEDIAN    AND    ULNAR    NERVES       275 

accident  of  great  severit}' ;  as  a  rule  many  tendons 
are  divided  in  addition  to  the  nerves.  Complete 
restoration  of  function  is  improbable  and  Avill 
certainly  not  take  place  unless  the  after-treatment  is 
carefully  carried  out  ;  it  will  then  require  at  least  two 
years  before  the  recognition  of  the  compass  test 
becomes  perfect. 


CHAPTER   XVII 

The  Cauda  Equina — Method  of  Injury — Symptoms  Produced — 
Distribution  of  Eoots,  Sensory  and  Motor — Examination 
and  Diagnosis — Prognosis — Treatment. 

These  injuries  acquire  tlieir  importance  from  the 
difficulty  which  often  exists  in  their  diagnosis  from 
injuries  of  the  spinal  cord,  a  diagnosis  which  is 
essential  to  correct  treatment. 

The  spinal  cord  terminates  at  the  level  of  the 
lower  border  of  the  first  lumbar  vertebra  in  the 
adult ;  in  early  life  it  occupies  more  of  the  spinal  canal. 

Below  the  level  of  the  twelfth  dorsal  vertebra  in 
the  adult  the  name  '^  conus  medullaris ''  is  given  to  it ; 
anatomically,,  this  portion  of  the  cord  is  defined  as 
that  below  the  level  of  origin  of  the  third  sacral 
roots. 

In  fracture  dislocations  or  penetrating  wounds  in 
the  lumbar  region  the  nerves  of  the  cauda  equina 
may  be  injured  alone,  or  in  association  with  the 
lower  portion  of  the  cord  (the  conus).  The  lumbar 
and  sacral  nerves  arise  close  together  and  their  roots 
run  downwards  inside  the  dura  mater,  forming  the 
Cauda  equina,  the  points  of  exit  of  these  roots  from 
the    theca   being    much    lower    than    their    place    of 


CAUDA    EQUINA  277 

origin  from  tlie  cord.  The  ^Dosterior  root  ganglia 
are  situated  outside  the  dura  mater,  so  that  in 
injuries  of  the  cauda  we  are  dealing  with  posterior 
and  anterior  roots.  It  must  be  remembered  that 
although  regeneration  of  posterior  roots  may  be 
possible  as  far  as  the  cord,  this  is  of  itself  useless, 
as  no  regeneration  of  intra-medullary  fibres  takes 
place ;  therefore,  complete  division  of  a  posterior 
root  central  to  its  ganglion  is  irremediable.  On  the 
other  hand,  after  complete  division  of  an  anterior 
root  recovery  proceeds  as  after  division  of  a  peri- 
pheral nerve. 

Injuries  to  the  cauda  equina  result  most  often 
from  a  fracture  dislocation  in  the  lumbar  region,  and 
the  nerves  may  be  injured  alone  or  with  the  conns. 
Fracture  dislocations  are  extremely  common  in  the 
dorsi-lumbar  region ;  in  fractures  below  the  level  of 
the  first  lumbar  vertebra  the  injury  Avill,  in  most 
cases,  aifect  the  cauda  alone  and  spare  the  conus  ; 
up  to  the  level  of  the  eleventh  dorsal  vertebra  it  may 
injure  the  cauda  alone,  but  as  a  rule  the  conus  also  is 
affected. 

Injury  to  the  cauda  alone,  or  in  association  with 
the  conus,  occasionally  results  from  a  fall  on  the 
back  or  buttocks  without  there  being  any  evidence 
of  bony  injury.  Such  a  case  has  recently  been 
under  my  care,  and  several  have  been  recorded. 

The  symptoms  produced  in  injuries  of  the  cauda 
equina    vary    with    the    extent    and    degree    of    the 


97>5 


78  INJURIES    OF    NERVES 

injury.  As  first  pointed  out  by  Thorburn,  when  the 
injury  is  incomplete  the  nerves  injured  are  usually 
lower  in  the  series  than  those  spared  :  for  example, 
interference  with  the  functions  of  the  bladder  and 
rectum,  and  alterations  of  sensibility  over  an  area  on 
the  buttocks  corresponding  to  the  supply  of  the  third 
sacral  roots  and  those  below  it  {vide  Fig.  22),  are 
present  in  practically  all  the  cases. 

The  same  changes  in  the  electrical  reactions  of  the 
affected  muscles  occur  as  after  injuries  of  peripheral 
nerves  of  a  corresponding  degree  of  severity. 

The  sensory  loss  is  of  the  root  type,  i.  e.  the  area 
of  loss  of  light  touch  is  smaller  than  the  area  of  loss 
of  sensibility  to  prick. 

The  sphincter  ani  is  paralysed  and  incontinence  of 
faeces  results ;  retention  of  urine  is  present  at  first, 
followed  in  many  cases  by  true  incontinence ;  sexual 
power  is  usually  absent,  but  the  testes  retain  their 
normal  sensibility,  being  supplied  from  a  higher  level 
than  the  angesthetic  skin  of  the  scrotum.  Sherrington 
and  Langley  and  Anderson  have  pointed  out  that 
the  bladder  and  rectum  have  a  double  nerve  supply 
from  the  last  dorsal  and  upper  lumbar  roots,  and 
from  the  sacral  roots  through  the  pelvic  splanchnics. 
The  exact  function  of  these  two  sets  of  fibres  has  not 
been  worked  out,  but  clinically,  lesions  of  the  lower 
set  cause  paralysis  of  the  bladder  and  rectum. 

The  following  illustrates  a  typical  lesion   due   to 
a  fracture  dislocation  of  the  second  lumbar  vertebra  : 


INJURY    OF    CAUDA    EQUINA 


279 


"A.P — ,  a  ship^s  carpenter,  aged  twenty-seven 
years,  fell  40  feet  into  a  ship's  liold,  alighting  on  liis 
back.     On  reoraininf^  consciousness  lie  found  that  his 


\\i 


Fig.  22. — To  sliow  loss  of  protopathic  sensilnlity  Avhieli 
i-esulted  from  an  injury  to  the  caiida  equina.  The  saddle- 
shaped  area  on  the  buttocks  is  that  resulting'  from  injury 
to  the  third  sacral  roots  and  those  below  it. 


legs  were  paralysed.  He  was  kept  in  bed  for  six 
weeks  ;  during  the  whole  of  this  time  retention  of 
urine  and  incontinence  of  feeces  were  present,  and 
these  s^-mptoms  did  not   improve  for  three  months. 


280  INJURIES    OF    SERVES 

He  began  to  regain  the  use  of  his  legs  at  the  same 
time_,  and  Avhen  I  saw  him  firsts  six  months  after  the 
accident_,  he  could  walk  with  the  aid  of  a  stick,  had 
perfect  control  of  his  urine  and  faeces,  and  had 
regained  sexual  power. 

"  Bony  deformity  was  present  in  the  region  of  the 
second  and  third  lumbar  vertebrae.  The  muscles  of 
both  lower  limbs  were  Avasted,  the  right  more  than 
the  left.  All  the  muscles  of  the  left  leg  acted,  and 
reacted  to  stimulation  with  the  interrupted  current. 
The  right  foot  was  in  the  position  of  talipes  equino- 
varus,  the  extensors  of  the  toes  and  the  peronei 
muscles  were  paralysed  and  gave  the  reaction  of 
degeneration,  but  the  tibialis  anticus  was  acting  and 
possessed  normal  electrical  reactions.  All  the  other 
muscles  of  the  leg  and  thigh  acted  normally. 
Sensation  was  altered  over  the  area  in  Fig.  22,  and 
showed  the  characteristic  features  of  root  injury. 
On  the  right  side  all  the  areas  from  the  fifth  lumbar 
downwards  were  aifected ;  on  the  left,  a  portion  of 
second  sacral  and  those  below  it." 

I  advised  laminectomy,  but  the  patient  would  not 
consent.  I  eventually  performed  complete  peri^Dheral 
anastomosis  of  the  external  to  the  internal  popliteal 
nerve.  This  operation  entirely  changed  the  character 
of  the  loss  of  sensibility  over  the  external  popliteal 
area.  From  being  of  the  root  type,  with  a  larger 
area  of  loss  of  sensibility  to  prick  than  to  light 
touch,  it  became  a  typical  area  of  loss  due  to  a  peri- 


INJURY    TO    CONUS    MEDULLARIS    281 

pheral  nerve  division  witli  a  loss  of  sensibility  to 
light  touch  larger  than  that  to  prick. 

This  case  is  in  every  way  typical  of  the  result  of 
an  injury  to  the  cauda  e(^uina  from  a  fracture  of  the 
lumbar  vertebrse,  at  first  complete  paralysis  of  the 
legs,  later  improving  and  leaving  some  permanent  dis- 
ability behind.  The  muscles  of  the  anterior  surface 
of  the  thigh  and  the  adductors  escape,  and  there  is  a 
sensitive  strip  on  the  inner  side  of  the  leg,  and  the 
anterior,  internal  and  external  aspects  of  the  thigh 
retain  their  sensibility.  The  distribution  of  the  loss 
of  motion  and  sensibility  is,  however,  often  asym- 
metrical. 

The  conus  medullaris  may  be  injured  alone  or 
more  often  with  the  nerves  of  the  cauda  equina. 
When  injured  alone,  paralysis  of  the  bladder  and 
rectum  results  with  a  small  patch  of  alteration  of 
sensibility  over  the  coccyx.  When  a  larger  area 
of  loss  is  present  we  must  assume  that  the  cauda  is 
injured  in  addition,  unless  the  injury  be  purely 
spinal  cord. 

Examination  and  diagnosis. — In  making  the  dia- 
gnosis, the  extent  of  the  lesion  (the  segments  or  roots 
involved)  and  its  degree,  whether  complete  or  incom- 
plete, must  be  settled,  and  its  position,  whether  cord, 
cauda,  or  both  combined.  It  must  be  remembered 
that  a  lesion  of  the  conus  and  cauda  combined  may, 
on  superficial  examination,  be  mistaken  for  an  injury 
of  the  spinal  cord  at  a  much  higher   level,  but  on  a 


282  INJURIES    OF    NERYES 

thorough  examination  the  typical  sensory  change  in 
the  latter  case  will  enable  the  diagnosis  to  be  made 
even  in  a  recent  case,  while  if  some  time  has 
elapsed  no  doubt  can  arise  from  the  muscular 
examination. 

The  examination  follows  the  lines  already  laid 
down.  To  make  the  diagnosis  of  the  seat  of  the 
lesion  and  the  roots  involved  it  will  be  necessary  to 
remember  roughly  the  sensory  and  motor  distribu- 
tion of  the  sacral  and  lower  lumbar  roots. 

From  the  sensory  standpoint  the  landmark  to 
remember  is  the  saddle-shaped  area  of  loss  of  sensi- 
bility on  the  buttocks  corresponding  to  the  third 
sacral  root  (vide  Fig.  23).  From  the  motor  side, 
that  the  muscles  supplied  by  the  external  popliteal 
(with  the  exception  of  the  tibialis  anticus)  are  those 
supplied  by  the  fifth  lumbar  root. 

The  sensory  diagram  (Fig.  23)  is  modified  from 
one  given  by  Gushing.  The  position  originated 
with  Gushing  and  shows,  better  than  any  previously 
joublished,  the  distribution  of  the  various  roots. 
The  remarks  made  in  speaking  of  the  distribution  of 
the  posterior  roots  entering  into  the  formation  of 
the  brachial  plexus  apply  here,  but  the  overlap  is 
less  and  the  areas  on  the  buttocks  may  be  taken  as 
the  exclusive  protopathic  supply  of  the  sacral  roots 
below  and  including  the  third. 

The  following  table  gives  roughly  the  distribution 
of  the    roots    to  the  various  muscles ;   the   remarks 


DISTRIBUTION    OF    SACRAL    ROOTS   283 

made  in  dealing  witli  a  similar  table  fur  the  brachial 
plexus  apply  here  also. 

Third  and  fourth  sacral. — Levator  ani ;   sphincter 
ani ;  perineal  muscles. 


Fig.  23. — Exclusive  protopatliic  supply  of  the  louver  sacral 
roots.  The  area  dotted  is  that  Avhich  usually  becomes 
insensitive  to  protopathic  stimiili  in  injuries  of  the  cauda 
equina.     (Modified  from  Gushing.) 


Second  sacral. — Glutei  muscles ;  biceps  ;  semi- 
membranosus and  semi-tendinosus. 

First  sacral. — Intrinsic  muscles  of  the  foot ;  tibi- 
alis posticus  and  other  calf  muscles. 

Fifth  lumbar. — Muscles  of  antero-external  surface 
of  leg  (except  tibialis  anticus). 


284  INJURIES    OF    [N^ERVES 

Fourth  lumbar. — Extensors  of  leg  and  tibialis 
anticus. 

It  is  difficult  to  make  this  table  absolutely  correct ; 
lesions  of  roots  are  rarer  even  than  in  the  cervical 
region. 


No  difficulty  should  be  experienced  in  diagnosing 
a  pure  cauda  lesion.  The  paralysis  is  of  the  peri- 
pheral type  with  segmental  distribution.  The 
sensory  loss  has  the  characteristic  features  of  an 
injury  to  posterior  roots. 

Most  of  the  lesions  are  incomplete ;  did  such  an 
injury  involve  the  spinal  cord^  light  touch  would  be 
everywhere  appreciated^  although  sensibility  to  prick 
might  be  lost  [vide  p.  65).  With  an  injury  to  the 
Cauda  equina,  light  touch  will  be  lost,  but  not  to  so 
great  an  extent  as  prick. 

Considerable  difficulty  may  arise  in  the  differential 
diagnosis  of  a  lesion  of  the  conus  from  one  of  the 
lower  sacral  roots.  A  pure  conus  lesion,  however, 
should  give  rise  to  no  difficulty,  the  paralysis  of  the 
bladder  and  rectum  with  a  small  area  of  sensory 
change  below  the  third  sacral  area,  the  loss  of  sensi- 
bility being  of  the  cord  type,  is  typical.  It  is  when 
the  two  are  combined  that  it  may  be  absolutely 
impossible  to  come  to  a  correct  conclusion,  except  by 
exploration  or  the  after-progress  of  the  patient. 

The  following  points  should  be  kept  in  mind : 
The  distribution    of   the    paralysis.      The  nature   of 


INJURIES   OF    CAUDA    EQUINA  285 

the  sensory  loss  :  if  cauda,  it  has  root  characteristics. 
Asymmetry  is  suggestive  of  a  lesion  of  the  cauda  ; 
improvement  of  symptoms  points  in  the  same 
direction. 

Prognosis. — This  cannot  be  said  to  be  good,  but 
may  be  improved  by  operation. 

Death  seldom  occurs  as  the  direct  result  of  an 
injury  to  the  cauda  equina ;  it  will  result  most  often 
from  urinary  infection.  Complete  recovery  is  rare  ; 
in  most  of  the  cases  spontaneous  recovery  is  incom- 
plete, as  in  the  case  I  have  quoted. 

Treatment. — The  surgery  of  the  cauda  equina  is  in 
its  infancy.  Both  in  traumatic  cases  and  also  as  a 
field  for  nerve  anastomosis  after  fractures  of  the  spine 
with  involvement  of  the  spinal  cord,  and  in  old  cases 
of  infantile  paralysis,  there  is  great  hope  of  success. 
The  nerves  lie  close  together  rendering  anastomosis 
easy. 

In  fracture  dislocation  of  the  spinal  cord  involv- 
ing the  Cauda  equina,  I  consider  that  operation 
should  be  carried  out  without  delay.  The  spinal 
canal  must  be  opened  up  and  the  dural  sheath  ex- 
posed ;  this  should  not  be  opened  until  careful  search 
has  been  made  for  signs  of  pressure  external  to  it. 
If  no  satisfactory  cause  is  found  for  the  symptoms,  the 
dura  must  be  opened  and  the  individual  roots  investi- 
gated. The  anterior  roots  can  be  distinguished  by 
stimulation  with  the  interrupted  current  for  a  few 
days  after  the  injury.      After  dealing  with  the  con- 


286  INJURIES    OF    NERVES 

ditiou  found  tlie  dura  is  closed;  the  bone  removed 
in  performing  the  laminectomy  should  not  be 
replaced. 

It  is  probable  that  no  great  harm  will  result  in 
leaving  the  patient  for  a  few  days  and  treating  as  a 
case  of  nerve  injury  elsewhere  and  watching  the 
reactions  of  the  paralysed  muscles,  but  it  is  to  be 
remembered  that  all  delay  makes  operative  inter- 
ference more  difficult,  and  that  the  long-continued 
pressure  on  the  roots  may  lead  to  their  degeneration ; 
if  this  takes  place  in  the  posterior  roots  complete 
recovery  is  impossible.  Whether  operation  is  carried 
out  or  no  the  usual  after-treatment  is  to  be  adopted. 

In  long-standing  cases  the  rules  governing 
operative  interference  in  long-standing  injuries  of 
peripheral  nerves  must  be  applied. 

When  the  paralysis  of  the  bladder  and  rectum  is 
permanent  as  the  result  of  injury  to  the  conus  or 
sacral  nerves  supplying  the  bladder,  intra-vertebral 
nerve  anastomosis  or  nerve  crossing  may  be  carried 
out  as  advised  by  Kilvington.  In  doing  this 
operation  sound  nerves  must  be  taken  outside  the 
dura  mater  to  innervate  the  injured  sacral  roots.  It 
is  possible  to  divide  the  twelfth  dorsal  nerve  in  its 
foramen  of  exit  and  bring  it  to  the  anterior  and 
posterior  roots  of  the  second,  third  and  fourth  sacral, 
cut  free  from  the  cord. 


CHAPTER    XVIII 

Injuries  to  the  Nerves  of  the  Lower  Limb — Lumbar  Plexus — 
Anterior  Crural  Nerve — Obtui'atcr  Nerve — External  Cutaneous 
Nerve  :  Bernhardt's  Disease — Sacral  Plexus — Paralysis  of 
Gluteal  Muscles — Great  Sciatic  Nerve :  Method  of  Injury : 
Motor  Symptoms :  Prognosis — External  Popliteal :  Injuries 
Above  and  Below  its  Lateral  Cutaneous  Branch. — Internal 
Popliteal  Nerve — Anterior  Tibial  Nerve. 

Injuries  to  tlie  nerves  of  the  lower  limb  are,  with 
the  exception  of  the  external  popliteal,  rare,  and  in 
most  instances,  subcutaneous. 

Injuries  of  the  lumbar  or  sacral  plexus  are  un- 
common, of  the  former  rare.  They  have  been  recorded 
as  a  complication  of  psoas  abscess  and  of  ojDeration 
for  its  cure,  as  the  result  of  pelvic  operations, 
prolonged  parturition,  fractured  pelvis  and  gunshot 
wounds. 

Anterior  crural  nerve. — This  nerve  is  rarely  affected. 
It  has  been  injured  as  a  complication  of  fractures  of 
the  pelvis  or  femur,  as  the  result  of  penetrating 
wounds,  during  the  course  of  operations  upon  psoas 
abscess,  and  as  the  result  of  the  abscess,  and  has 
suffered  from  manipulations  carried  out  for  the 
treatment  of  congenital  dislocation  of  the  hip- joint. 

Its  division  is  rarely  complete. 


288  INJURIES    OF    NERVES 

The  most  important  symptom  is  the  paralysis  of 
the  quadriceps  extensor  cruris.  There  should  be  no 
difficulty  in  the  diagnosis  of  this ;  the  patient  is 
unable  to  extend  the  leg.  He  can^  however^  bring  it 
forward  in  walking  by  using  the  adductors  after 
the  leg  has  been  everted. 

Sensation  is  affected  over  an  extremely  well- 
defined  area  in  the  leg  (Plate  XVII)  and  over  an  ill- 
defined  area  on  the  antero-lateral  aspect  of  the 
thigh.  In  the  lower  two  thirds  of  the  leg  epicritic 
and  protopathic  sensibility  are  lost  over  an  area 
which  has  well-marked  borders.  At  its  upper  part 
the  boundaries  become  ill  defined  and  it  merges  into 
an  area  on  the  anterior  and  internal  aspects  of  the 
thigh,  in  which,  as  a  rule,  there  is  no  complete  loss 
of  any  form  of  sensibility. 

Obturator  nerve.  — Isolated  injury  of  this  nerve  is 
less  often  met  with  even  than  an  injury  to  the 
anterior  crural.  The  lesion  is  usually  incomplete 
and  occurs  as  a  complication  of  protracted  labour, 
particularly  when  forceps  have  been  necessary.  It 
may  also  be  injured  in  thyroid  dislocations  of  the 
hip  and  in  the  rare  obturator  hernia.  Pain  may  be 
experienced  in  its  sensory  distribution  on  the  inner 
side  of  the  knee  in  cases  of  irritative  lesion. 

The  adductors  are  paralysed  as  the  result  of  its 
injury,  with  the  exception  of  the  flexor  portion  of 
the  adductor  magnus  which  is  supplied  by  the  great 
sciatic.      Its   complete   division  produces  no   loss    of 


PLATE   XVII. 


Showing-  the  loss  of  sensibility  in  lower  part  of  the  leg  after  division 
of  the  anterior  crnral  nerve. 


To  face  p.  283. 


Adlard  S-  Son,  Impr. 


EXTERNAL  CUTANEOUS  NERYE    289 

sensibility  as  the  nerve  lias  no  exclusive  sensory 
supply. 

There  should  be  no  difficulty  in  diagnosis ;  the 
affection  of  the  adductors  is  not  easily  overlooked. 

The  external  cutaneous  ner^e. — It  is  rarely  that  this 
nerve  is  divided ;  it  sometimes  suffers  in  operations 
upon  a  psoas  abscess  or  other  operative  procedures 
in  the  iliac  fossa  or  upper  portion  of  the  thigh. 

It  supplies  exclusively  with  epicritic  and  proto- 
pathic  sensibility  an  area  on  the  outer  side  of  the 
thigh  in  its  upper  third ;  deep  touch  is  unaffected 
after  its  division. 

This  nerve  is  of  more  importance  in  connection 
with  Bernhardt^s  disease  or  meralgia  paraesthetica. 
This  condition^  which  is  characterised  by  pain  in  the 
distribution  of  this  nerve^  usually  with  alterations 
in  sensibility^  was  described  by  Bernhardt  in  1895, 
who  was  followed  in  a  few  months  by  Roth.  It  is 
most  common  in  males  and  usually  arises  as  the 
result  of  injurj^  In  some  cases  the  injury  is  long- 
continued,  such  as  the  pressure  of  a  badly-fitting 
truss  j  in  other  cases  pain  has  originated  after  the 
patient  has  over-reached  or  strained  himself,  the 
nerve  probably  suffering  at  its  exit  from  the  deep 
fascia. 

A  feeling  of  tingling  or  of  coldness  in  the  sensory 
distribution  is  usually  the  first  symptom  to  attract 
attention ;  this  increases  and  pain  is  experienced  on 
standing  or  walking,  and  disappears  on  resting.      A 

19 


290  INJURIES    OF    NERVES 

tender  swelling  is  sometimes  present  just  where  the 
nerve  issues  from  under  Poupart^s  ligament  and 
runs  in  the  deep  fascia.  The  skin  in  the  territory 
supplied  by  the  nerve  shows  changes  in  sensibility  ; 
as  a  rule  sensibility  to  light  touch  is  defective  and 
there  is  an  area  of  changed  sensibility  to  the  point 
of  a  pin. 

Treatment. — In  those  cases  due  to  long-continued 
pressure^  removal  of  the  cause  followed  by  rest 
should  be  first  tried.  If  this  fails  to  give  relief  or 
the  condition  has  supervened  on  a  sudden  injury, 
resection  of  the  damaged  portion  of  the  nerve 
followed  by  end-to-end  suture  Avill  cure  the  condition^ 
but  this  is  useless  unless  there  has  been  some  definite 
injury  to  the  nerve,  followed  by  definite  change  in 
its  trunk. 

Long  (internal)  saphenous  nerve. — This  nerve  is 
occasionally  divided  during  an  operation  upon  a 
varicose  internal  saphenous  vein  or  ligature  of  the 
femoral  artery  in  Hunter^s  canal.  Plate  XIX  gives 
its   exclusive   supply  in   the   leg. 

Gluteal  nerves.— The  gluteal  muscles  are  supplied 
by  the  superior  and  inferior  gluteal  nerves.  These 
rarely  suffer  alone  ;  they  are  most  often  affected  in 
injuries  of  the  plexus  itself. 

The  superior  gluteal  nerve  which  winds  round  the 
lower  border  of  the  ilium  is  sometimes  pressed  upon 
in  gluteal  aneurysm  or  abscess,  and  may  be  injured 
during  the  course  of  operations  in  this  situation. 


GLUTEAL    NERYES  291 

Paralysis  or  weakness  of  the  glutei  muscles  of 
both  sides  as  seen  in  injuries  of  the  cauda  equina 
produces  a  waddling  gait  with  lordosis.  Para- 
lysis of  the  glutei  muscles  of  one  side  only  is 
easily  diagnosed ;  the  flattening  of  the  buttock  and 
failure  of  action  of  the  muscles  is  obvious.  The 
action  of  the  gluteus  maximus  is  best  tested  by 
attempts  at  extension  of  the  thigh  or  in  rising  from 
a  stooping  position.  Paralysis  of  the  gluteus  medius 
and  minimus  alone  is  difficult  of  diagnosis^  but  weak- 
ness of  outward  rotation  of  the  limb  is  present,  and 
the  paralysis  of  the  tensor  fascias  f  em  oris  will  enable 
the  diagnosis  of  an  injury  to  the  superior  gluteal 
nerve  to  be  made. 

The  great  sciatic  nerve.— Li juries  to  the  sciatic 
nerve  are  rare  in  civil  practice,  but  it  suffers  from 
gunshot  injuries  more  often  than  any  other  nerve. 
In  addition  to  penetrating  wounds,  injury  may  result 
from  the  manipulations  necessary  in  the  treatment  of 
congenital  dislocation  of  the  hip,  occasionally  as  the 
result  of  a  traumatic  dislocation,  or  its  reduction,  or  it 
may  suffer,  with  other  branches  of  the  sacral  plexus, 
in  fractures  of  the  pelvis. 

It  must  be  remembered  that  for  surgical  jDurposes 
the  great  sciatic  nerve  consists  of  two  separate 
nerves,  the  external  and  internal  popliteal,  and  that 
these  remain  separate  up  to  the  point  at  which  they 
are  given  off  from  the  plexus.  Either  nerve  may  be 
injured    alone   in   an   accident    to   the   great  sciatic. 


292  INJURIES    OF    NERVES 

Hence  incomplete  division  of  this  nerve  may  differ 
from  that  of  other  nerves.  In  incomplete  injuries  of 
the  great  sciatic  its  external  popliteal  portion  suffers 
more  often  ;  this  occurs  not  only  in  subcutaneous 
injuries,  such  as  those  produced  in  manipulating 
congenital  dislocations  of  the  hip,  but  also  as  the 
result  of  a  penetrating  wound.  In  the  gunshot 
wounds  of  this  nerve  which  have  come  under  my 
notice  it  Avas  particularly  noticeable.  This  is  in 
agreement  with  Makins^  experience.  He  states : 
^^  The  most  striking  observation  with  regard  to 
injuries  of  the  great  sciatic  was  the  comparatively 
frequent  escape  of  the  popliteal  element  (internal 
popliteal)  and  the  severe  lesion  of  the  peroneal. 
This  Avas  so  pronounced  as  to  amount  to  as  high 
a  proportion  of  peroneal  symptoms  as  90  per 
cent.      .      .      :' 

It  is  therefore  obvious  that  an  incomplete  injury 
to  the  great  sciatic  nerve  may  produce  a  complete 
division  of  the  external  popliteal  nerve  without 
affecting  the  internal. 

No  satisfactory  explanation  of  this  is  forthcoming. 
The  exposed  position  of  the  fifth  lumbar  anterior 
primary  division  and  the  posterior  position  of  the 
external  popliteal  element  of  the  great  sciatic  nerve 
in  the  thigh  may  have  something  to  do  with  this. 
But  we  must  remember  that  the  external  poj^liteal 
group  of  muscles  suffers  frequently  in  other  nervous 
conditions;  for  example,   in  infantile  paralysis  it    is 


GREAT    SCIATIC    NERVE  293 

the  group  most  often  permanently  paralysed^  and  it 
is  often  picked  out  in  toxic  neuritis.  Daus,  in  a 
research  upon  the  subject_,  could  arrive  at  no  satis- 
factory conclusion  ;  he  simply  states  that  the  nerve 
is  more  vulnerable  than  the  internal  popliteal^  and 
quotes  experiments  by  Gerardt^  j^^i^v  i^^  which;  after 
the  death  of  animals  the  extensor  muscles  of  the  leg 
lost  their  electrical  excitability  before  the  flexors. 
Hofman  came  to  the  conclusion  that  a  difference  in 
their  blood  supply  accounted  for  the  more  frequent 
affection  of  the  external  popliteal ;  it  receives  a 
smaller  branch  from  the  comes  nervi  ischiatici  than 
the  internal.  It  is  difficult  to  believe  that  this  is 
the  explanation. 

Complete  division  of  the  great  sciatic  nerve  is 
uncommon  ;  in  sixteen  patients  that  have  come  under 
my  notice  with  injury  to  this  nerve  in  two  only  was 
the  division  complete. 

Motor  symptums. — After  section  of  the  great  sciatic 
nerve  all  the  muscles  of  the  leg  are  paralysed  and 
all  movements  of  the  foot  impossible.  If  divided  in 
the  upper  part  of  the  thigh  the  hamstring  muscles 
are  paralysed.  But  although  these  muscles  are  not 
acting',  flexion  of  the  leg  on  the  thigh  is  still  possible 
by  means  of  the  gracilis  ;  in  long-standing  cases  this 
muscle  becomes  hypertrophied  and  a  very  efficient 
flexor.  This  has  led  to  errors  in  diagnosis  through 
non-observance  of  the  rule  that  the  action  of  in- 
dividual  muscles    must   be    investigated,  the    flexion 


294  INJURIES    OF    NERVES 

of  tlie  lesf  beino'  considered  due  to  the  action  of 
tlie  hamstring  muscles  supplied  by  the  great 
sciatic. 

Sensory  symptoms. — There  is  a  widespread  loss  of 
sensibility  below  the  knee^  a  strip  on  the  inner  side^ 
the  full  supply  of  the  internal  saphenous  alone 
remaining  sensitive.  The  borders  of  the  area  of  loss 
of  epicritic  and  protopathic  sensibility  are  almost  co- 
terminous^ except  above  {vide  Plates  XYIII,  ^I^)^ 
and  are  well  defined.  In  spite  of  the  widespread  loss 
of  sensibility  deep  touch  is  affected  only  over  a  com- 
paratively small  area  of  the  foot.  This  has  led  to 
diagnostic  errors.  Within  the  area  of  loss  of  proto- 
pathic sensibility  deep  touch  may  be  well  developed, 
the  patient  recognising  pressure  immediately  and 
localising  it  well. 

Prognosis. — After  suture  of  the  great  sciatic, 
months  must  elapse  before  the  patient  regains  a 
useful  limb.  Sensibility  to  deep  touch  is  first 
regained,  and  the  foot  should  be  everywhere  sensitive 
to  this  form  of  stimulation  in  from  three  to  six 
months.  About  eight  weeks  after  suture,  in  an  un- 
complicated case,  the  area  of  loss  of  protopathic 
sensibility  should  begin  to  improve,  but  months  will 
elapse  before  it  is  everywhere  appreciated.  No 
alteration  in  the  extent  of  the  epicritic  loss  is  to  be 
expected  before  eighteen  months. 

The  first  muscles  to  regain  voluntary  power  and 
electrical  excitability,  after  suture  or  after  an  incom- 


PLATE    XYIII. 


Shovvinf^  the  loss  of  sensibility  resulting  from  division  of  the  great  sciatic 
nerve.  The  area  of  loss  of  epicritic  sensibility  is  bounded  by  a  thin  line, 
dotted  at  its  ujjper  part ;  the  area  of  protopathic  loss  by  crosses,  the  thick 
line  bounds  the  area  of  loss  of  deep  touch.  The  unshaded  area  is  the  inter- 
mediat<;  zone,  the  oblique  shading  the  area  of  loss  of  epicritic  and  proto- 
yjathic  s(;nsi}>ility,  th(i  area  of  cross  shading  that  in  which  all  forms  of 
sensibility  are  absent. 


To  face  p.  201. 


Adlarcl  4"  So)i,  Impr, 


PLATE    XIX. 


For  description  see  Plate  XVIII. 


To  face  p.  294. 


Adlard  .j-  Soti,  Impr. 


GREAT    SCIATIC    NERVE:    PROGNOSIS    295 

plete  injury  of  the  wliole  nerve  in  the  upper  part 
of  the  thigh^  are  the  hamstrings.  This  may  be  ex- 
pected in  about  a  year  after  suture,  but  two  years  will 
probably  elapse  before  any  change  takes  place  in  the 
muscles  of  the  leg,  and  complete  muscular  recovery 
is  unlikely  under  three  years.  The  internal  popliteal 
group  regains  power  before  the  external. 

The  prognosis  in  all  cases  of  injury  to  this  nerve 
is  more  unfavourable  than  after  injuries  of  a  similar 
degree  affecting  nerves  of  the  upper  limb.  This  has 
chiefly  to  do  with  the  time  which  must  elapse 
between  suture  and  recovery ;  unless  the  nutrition  of 
the  skin  and  muscles  is  carefully  maintained  and 
care  taken  to  prevent  overstretching  of  the  paralysed 
muscles  the  result  will  be  poor,  even  although  nerve 
regeneration  has  taken  23lace. 

Treatment. — In  dealing  with  instances  of  incom- 
plete interruption  of  continuity  in  the  great  sciatic 
nerve  we  must  be  prepared  to  treat  complete  division 
of  its  external  popliteal  portion.  This  must  be  dealt 
with  as  complete  division  elsewhere ;  if  after  an 
injury  to  the  great  sciatic,  the  reaction  of  degenera- 
tion develops  in  the  external  popliteal  group  of 
muscles,  even  although  those  supplied  by  the  internal 
popliteal  are  unaffected,  the  nerve  should  be  exposed, 
the  damaged  portion  of  the  external  popliteal  found 
by  tracing  it  up  from  below,  separated  from  the 
internal,  excised  and  reunited.  During  the  early 
stages    of    recovery    the    weight   of   the   body  must 


296  INJURIES    OF    NERVES 

D^t  be  allowed  to  rest  on  tlie  paralysed  foot;  perfora- 
ting ulcers  are  liable  to  develop  and  may  necessitate 
amputation.  Tlie  foot  and  leg  should  be  fitted  witli 
a  light,  well-padded  poroplastic  splint  to  prevent 
deformity  and  the  patient  allowed  to  get  about  on  a 
bucket  leg  with  the  limb  flexed. 

No  time  after  the  injury  is  too  long  to  attempt 
operation ;  amputation  should  not  be  advised  as  a 
routine  measure  even  in  old  cases.  The  tendency  to 
the  formation  of  perforating  ulcers  ceases  with  the 
restoration  of  protopathic  sensibility,  and  this  is  to  be 
expected  in  every  case  in  which  the  wound  heals 
without  suppuration.  At  the  end  of  the  first  stage 
of  recovery  the  whole  of  the  sole  of  the  foot  is  in 
that  condition  of  sensibility  found  in  the  intermediate 
zone.  All  stimuli  have  an  unpleasant  tingling 
radiating  character,  and  for  this  reason  the  limb  may 
be  useless,  the  patient  being  unable  to  bear  an}^ 
weight  on  it.  This  will,  in  most  cases,  be  only  a 
stage,  and  as  epicritic  sensibility  is  restored  the 
tenderness  gradually  diminishes.  If  sensory  recovery 
fails  at  this  stage,  amputation  ma}^  be  necessary  on 
account  of  the  tenderness  and  pain ;  if  this  is  done 
care  should  be  taken  to  obtain  the  flap  from  the 
inner  side  of  the  leg,  from  skin  supplied  with  normal 
sensibility  by  the  internal  saphenous. 

If  complete  motor  recovery  fails  a  suitable  surgical 
boot  should  be  worn,  or  atbrodesis  of  the  ankle 
carried  out. 


PLATE   XX. 


To  show  the  loss  of  sensibility  produced  by  complete  division 
of  the  small  sciatic  nerve. 


To  face  p.  207. 


Adlarcl  ^  Son,  Imj^r, 


SMALL    SCIATIC    NERVE  297 

The  small  sciatic  nerve. — This  is  rarely  injured 
alone  but  suffers  in  lesions  of  tlie  sacral  plexus. 

Epicritic  and  iDrotopatliic  sensibility  are  lost  as 
the  result  of  its  com^^lete  division  over  the  rela- 
tively small  area  shown  in  Plate  XX.  Deep  sensi- 
bility is  unaffected. 

The  external  popliteal  nerve. — This  is  more  often 
injured  than  any  other  nerve  of  the  lower  limb.  It 
may  suffer  when  bound  up  with  the  internal  popliteal 
to  form  the  great  sciatic^  or^  after  it  has  sej)arated, 
above  or  below  the  point  at  which  its  lateral  cutaneous 
branch  is  given  off.  Injury  in  the  last  position  is 
the  most  common. 

Anatomical  division  of  the  nerve  is  rare^  but  it 
has  occurred  during  tenotomy  of  the  biceps  tendon 
and  during  the  forcible  straightening  of  a  jSexed 
knee-joint.  It  suffers  most  often  after  it  has 
separated  from  the  internal  popliteal^  from  direct 
violence  and  in  association  with  fractures  of  the 
neck  of  the  fibula^  the  nerve  injury  being  primary 
and  caused  by  the  injury  producing  the  fracture. 
From  its  exposed  position  on  the  neck  of  the  fibula 
it  is  exposed  to  external  injary^  and  suffers  not 
infrequently  from  the  faulty  application  of  Clover's 
crutch;  Bsmarch^s  bandage  or  puttees.  It  is  occa- 
sionally overstretched_,  and  sometimes  ruptured, 
during  the  forcible  extension  of  a  flexed  and  anky- 
losed  knee.  It  is  occasionally  involved  in  those  whose 
occupation  entails  work  in  a  crouching  attitude. 


298 


mJURIES    OF    NERVES 


Symptoms. — No  difficulty  in  tlie  diagnosis  is 
likely  to  arise  from  the  motor  side.  Tlie  foot  is  in 
tlie  position  of  talipes  equino-varuSj  and  tlie  tibialis 
anticuSj  all  tlie  extensors  of  the  toes  and  the  peronei 
muscles  are  paralysed.  Consequently  the  foot  cannot 
be  flexed  or  everted  and  the  toes  cannot  be  ex- 
tended. 

Difficulties  may  arise  in  the  interpretation  of  the 


Fig.  24.  — Illustrating  the  loss  of  sensibility  resulting  from 
division  of  the  external  popliteal  nerve  below  its  lateral 
cutaneoiTS  branch. 

loss  of  sensibility.  Deep  sensibility  is  unaffected, 
and  the  patient  may  be  able  to  appreciate  and  to 
localise  the  slightest  pressure  causing  deformation  of 
the  skin.  Just  before  the  nerve  passes  round  the 
neck  of  the  fibula  it  gives  off  a  large  lateral  cutaneous 
branch ;  it  is  most  often  injured  below  this  point. 
''J''ho  loss  of  sensibility  which  results  from  this  lesion 
is  only  absolute  on  the  dorsum  of  the  foot  and  lower 
tliird    of    tlie    leg    {vide    Fig.    24).        The    anterior 


EXTERNAL    POPLITEAL    NERVE 


299 


boundary  of  the  area  insensitive  to  light  touch  is  as 
well  defined  as  after  division  of  the  whole  nerve^ 
but  its  posterior  border  and  that  on  the  outer  margin 
of  the  foot  merge  gradually  into  parts  of  normal 
sensibility.  Sensibility  to  prick  is  abolished  over  a 
triangular  area  on  the  dorsum  of  the  foot_,  but  is 
defective    over    an    area    almost    as    large    as    that 


Fig.  25. — To  show  the  loss  of  sensibility   resulting   from 
division  of  the  whole  external  i3ox)liteal  nerve  above. 


anEesthetic  to  cotton- wool.  After  division  of  the 
nerve  in  this  situation  similar  phenomena  may  be 
observed  to  those  seen  after  division  of  the  ulnar 
below  its  dorsal  branch. 

Division  above  the  lateral  cutaneous  branch 
produces  an  area  of  loss  of  sensibility  on  the  outer 
side  of  the  leg  and  dorsum   of   the    foot   with  well- 


300  INJURIES    OF    NERVES 

defined  boundaries^  except  at  its  external  border  in 
tlie  lower  third  of  the  leg  and  outer  surface  of  the 
foot^  which  territory  it  supplies  in  common  with  the 
external  saphenous  nerve  {vide  Fig.  25).  The 
boundaries  of  the  loss  of  light  touch  and  of  prick 
are  almost  co-terminous. 

It  is  essential  to  remember  the  difference  in  the 
loss  of  sensibility  that  results  from  division  above 
and  below  this  branch.  The  small  loss  of  sensibility 
that  results  from  division  in  the  latter  situation  is 
not  sufficiently  well  recognised^  and  has  lately  led 
to  the  report  of  two  cases  of  "  injmediate  sensory 
recovery  "  after  suture.  Delbet^  in  a  discussion  on  the 
results  which  follow  division  of  the  external  popliteal 
nerve^  pointed  out  the  slight  loss  which  arises  when 
the  nerve  is  divided  in  this  situation.  I  have  been 
unable  to  find  any  other  reference  to  this  fact. 

Diagnosis. — Injury  to  the  fifth  lumbar  root  in  the 
spinal  canal^  or  to  the  fifth  anterior  primary  division 
as  it  crosses  the  brim  of  the  pelvis^  will  give  rise  to 
symptoms  resembling  those  of  division  of  the  external 
popliteal. 

The  seat  of  the  injury  must  be  settled^  whether 
with  the  great  sciatic  or  below  this^  above  or  below 
the  point  at  which  its  lateral  branch  is  given  off. 
A  consideration  of  the  nature  of  the  accident  will 
lead  to  the  correct  diagnosis  in  most  cases^  but  the 
symptoms  will  also  point  out  the  correct  seat. 
Injury  to  the  fifth  anterior  root  or  anterior  primary 


EXTERNAL    POPLITEAL    NERVE  301 

division  usually  leaves  the  tibialis  anticus  muscle 
unaffected;  in  an  injury  to  the  lumbo-sacral  cord  or 
external  popliteal  nerve  this  muscle  is  paralysed. 
An  injury  of  the  fifth  anterior  root  leaves  sensibility 
unaffected;  if  the  posterior  root  is  affected  in  addition, 
the  loss  of  light  touch  is  less  extensive  than  the  loss 
of  sensibility  to  prick.  This  was  beautifully  shown 
in  a  patient  with  involvement  of  these  roots  in  a 
Cauda  equina  injury,  on  whom  I  divided  the  external 
popliteal  nerve  for  purposes  of  anastomosis.  Before 
his  operation  the  loss  of  sensibility  was  of  the  root 
type ;  after,  it  showed  the  typical  features  of  the  loss 
of  sensibility  resulting  from  division  of  a  peripheral 
nerve. 

Treatment. — Attention  must  be  directed  to  the 
necessity  for  preventing  foot  drop.  Complete  recovery 
is  impossible  in  a  patient  whose  paralysed  muscles 
have  been  over-stretched  for  a  considerable  time. 
The  foot  must  be  kept  at  right  angles  to  the  leg  in 
a  light  poroplastic  splint ;  later,  the  patient  may  be 
allowed  to  walk  on  the  affected  limb  with  a  surgical 
boot  fitted  with  a  toe-raising  spring*.  At  night  the 
splint  should  be  worn  until  the  muscles  have  regained 
voluntary  power. 

Involvement  in  fractures. — As  already  mentioned, 
this  nerve  is  not  infrequently  injured  in  fractures  of 
the  upper  end  of  the  fibula.  The  injury  is,  in  most 
cases,  physiological,  but  a  case  has  been  recorded 
by  Duplay  in  which  the  nerve  was  found  completely 


302  INJURIES    OF    NERVES 

ruptured.  The  nerve  usually  passes  between  the 
fragments^  and  unless  operation  is  undertaken  the 
division  becomes  complete.  In  all  cases  of  fracture 
of  the  upper  end  of  the  fibula  with  involvement  of 
this  nerve^  if  there  is  any  separation  of  the 
frao-ments,  primary  operation  should  be  undertaken^ 
the  nerve  freed^  and  the  fragments  exposed  and 
wired,  or  the  small  upper  fragment  may  be  completely 
removed,  care  being  taken  to  injure  the  attachment 
of  the  biceps  as  little  as  possible.  If  the  nerve 
be  found  ruptured,  suture,  after  trimming  the  ends 
with  a  sharp  scalpel,  should  be  carried  out.  When 
the  fragments  are  in  close  apposition  immediate 
operation  is  unnecessary  ;  the  usual  treatment  for  a 
subcutaneous  injury  should  be  instituted.  In  old 
cases  in  which  the  reaction  of  degeneration  has 
developed,  excision  of  the  damaged  portion  of  the 
nerve  must  be  carried  out ;    neurolysis  is  useless. 

Recovery  and  fvognosis. — The  tibialis  anticus  is 
the  muscle  which  first  regains  voluntary  power 
and  electrical  excitability,  followed  by  the  extensors 
of  the  toes,  and  lastly  the  peronei ;  these  latter 
muscles  may  remain  permanently  paralysed. 

Recovery  will  follow  in  most  cases  if  the  appro- 
priate treatment  and  after-treatment  is  carried  out, 
and  may  be  expected  to  become  complete  in  about 
three  years.  But  if,  after  suture,  no  care  is  taken, 
complete  recovery  never  takes  place. 

Internal  popliteal  nerve. — Injury  to  this  nerve  is 


ANTERIOR    TIBIAL    NERVE  303 

uncommon ;  it  has  occurred  during  the  forcible 
straightening  of  a  flexed  and  ankylosed  knee. 

The  calf  muscles,  the  tibialis  anticus  and  flexors 
of  the  toes  are  paralysed,  and  the  foot  takes  up  the 
jDOsition  of  talipes  calcaneo  valgus  ;  extension  of  the 
foot,  inversion  in  the  extended  position  and  flexion 
of  the  toes  are  impossible.  No  difficulty  arises  in 
recognising  the  paralysis  of  the  muscles  concerned 
in  these  movements. 

There  is  no  loss  of  deep  sensibility  after  complete 
division  of  this  nerve,  but  epicritic  and  protopathic 
sensibility  are  lost  over  the  sole  of  the  foot.  This 
area  has  a  well-defined  inner  border,  but  the  outer 
border  is  ill  defined  owing  to  its  overlap  with  the 
external  saphenous.  The  dorsal  surface  of  the  outer 
four  toes  is  insensitive  to  epicritic  stimuli,  but  there 
is  no  loss  of  protopathic  sensibility  over  their  dorsal 
or  plantar  surfaces. 

Anterior  tibial  nerve. — This  nerve  is  rarely  injured 
alone  on  account  of  its  deep  position,  but  occasionally 
it  is  pressed  upon  or  lacerated  in  fractures  of  the 
tibia,  and  may  give  rise  to  all  the  symptoms  of 
irritative  involvement  of  a  nerve. 

Anatomically,  filaments  of  this  nerve  may  be  traced 
to  the  cleft  between  the  great  and  second  toes^  but 
it  has  here  no  exclusive  supply.  I  have  on  two 
occasions  divided  this  nerve  for  therapeutic  purposes 
and  failed  to  produce  any  loss  of  sensibility  in  this 
situation. 


INDEX 


Abduction  of  thumb,  27,  268 
Acusesthesia,  54 
Adduction  of  thumb,  248 
Anastomosis,  nerve,  86 

—  in  Cauda  equina  lesions,  285 

—  in  facial  paralysis,  168 

—  in  injuries  of  nerves,  92 
spinal  cord,  286 

—  varieties  of,  92 
Anterior  crural  nerve,  287 

—  tibial  nerve,  303 

injury  in  fractures,  43, 

141,  303 
Antidromic  impulses,  139 
Auditory  nerve,  172 
Autoplastie  nerveuse,  89 

Bernhardt's  disease,  289 
Birth  paralysis,  brachial,  206 

facial,  164 

Blisters    arising  after  complete 
division,  21 

—  arising-       after       incomplete 
division,  44 

—  arising   diu-ing   recovery,   73, 

103,  118 


Brachial  plexus,  183 

birth  paralysis,  206 

distribution  of  roots  enter- 
ing, 184 

injuries  of,  from   cervical 

ribs,  190 

^-  complete,  194 

infra-clavicular,  193 

—  inner  cord,  200 

—  localisation  of,  225 

oiiter  cord,  19,  201 

post-ansesthetic,  189 

—  —  —  prognosis  of,  204 
—  supra-clavicular,  187 

—  —  —  traction,  197 
-with  fractured  clavicle 

192 

Causalg-ia,  42,  137 
Cauda  equina,  276 

diagnosis  of  injuries  of,  284 

Cervical  nei'ves,  178 

—  ribs,     injuries     of      brachial 

plexus,  associated  with,  190 

—  sympathetic,  181,  194,  225 
injmy  of,  181,  182 

'  20 


306 


INDEX 


Cervical  sympathetic,  injury  with 

brachial  plexus,  194,  200 
Change,  line  of,  19,  38,  50,  107 
Chorda  tympani  nerve,  164 
Circumflex  nerve,  216,  227 
Classification  of  nerve  injuries,  2 

—  of  brachial  plexus  injiiries,  187 
Compass  test,  51 

restoration  of,  after  divi- 
sion, 107,  124 

Complications  during  recovery 
after  complete  division,  118 

after  incomplete    division, 

132 

Contractures,  28,  117 

—  hysterical,  69 

—  facial,  166 

—  ischsemic,  70 
Conus  meduUaris,  276 

injuries  of,  281 

Corneal  changes,  161,  163 
Crossing,  nerve,  86,  95 

—  —  in  facial  paralysis,  169 
Crutch  paralysis,  musculo -spiral, 

232,  234 
circumflex,  217 

Deep  sensibility,  17,  20 

—  —  recovery  of,  108 

tests  for,  54 

Degeneration,  reaction  of,  28 
Deltoid  muscle,  paralysis  of,  199, 

216,  226 
Diagnosis  of  nerve  injuries,  45,  61 

from  hysteria,  66 

from  ischsemic  contracture, 

70 
from  spinal  cord  injuries, 

61,  222 


Diagnosis  of  brachial  plexus  in- 
juries, 219 

Diplopia,  153 

Dislocations, nerve  injury  compli- 
cating, 9 

—  injury  of  anterior  crural  nerve, 

287 

of  brachial  plexus,  200 

of  musculo-spiral  nerve,  233 

of  obstructor  nerve,  288 

—  —  of  sciatic,  great,  291 

of  ulnar  nerve,  256 

Division,  anatomical,  2 

—  complete,  15 

—  definition  of,  2 

—  in  woimds,  3 

—  incomplete,  35 

—  X^^ysiolOoical,  2 

Dorsal  nerves,  operative  injuries 

of,  5,  144,  146 
Electrical  reactions,  in  complete 

division,  28 

in  incomplete  division,  55 

Electrical  testing,  55 

—  treatment,  73 
End  bulbs,  142 
Epicritic  sensibility,  21 

recovery  of,  101,  123 

tests  for,  48 

Erb,  see  Paralysis. 
Examination,  methods  of,  45 
External    cutaneous    nerve    (of 

forearm),  230,  233 
(of  leg),  289 

—  popliteal  nerve,  297 

injury  with  great  sciatic, 

293 
in  fractures,  301 

Facial  nerve,  164 


INDEX 


307 


Facial  nerve  anastomosis,  169 

•  birth  paralysis  of,  164 

distribution,  165 

paresis    of    muscles    after 

removal  of  Gasserian  gan- 
glion, 161 

—  —  prognosis,  166 
Fifth  cranial  nerve,  154 

—  —  corneal       changes       after 

injiuy  of,  162 

—  —  distribution,  sensory,  154 

—  —  —  motor,  160 

—  —  first  division,  161 

—  —  second  and  third  division, 

163 
Fractures,  injuries  of  nerves  in, 

7,82 
of  brachial  plexus  in,  187, 

192 
of    external   popliteal    in, 

297,  301 

of  musculo-spiral  in,  234 

of  ulnar  nerve  m,  256 

Fracture  of  base  of  skull,  nerve 

injxiry  in,  150 
Fractux'es      of     spine,     cervical 

region,  222 
lumbar  region,  277 

Glosso-pharyngeal  nerve,  172 
Glossy  skin,  32,  42,  132,  137 
Gluteal  nerve,  290 
Gunshot  wounds,  see  Wounds. 
Ganglion,  Gasserian,  removal  of, 

155 
injuries  of  nerves  in,  152 

—  posterior  root,  removal  of,  143 

Horner's    muscles,   paralysis    of, 
165 


Hypoglossal  nerve,  177 

—  anastomosis,  169 
Hyperalgesia,  41,  132 
Hysteria,  66 

—  diagnosis  from  nerve  injury, 

143 

Injury,  nerve,  by  pressure,  6 

by  traction,  7 

-by  wounds,  3 

in  wounds,  gunshot,  12 

operative,  9 

complicating   fractures,  7, 

82 
Ilio-hypogastric  nerve,  5,  144 
Ilio-ingidnal  nerve,  5,  144,  145 
Inferior  dental  nerve,  163 
Internal  cutaneous  nerve,  245 

—  popliteal  nerve,  302 

—  saphenous  nerve,  290 
Intercosto-himieral  nerve,  146 

Joints,  changes  in,  33 

Klumpke,  see  Paralysis. 

Lacrymation    after    removal    of 
Gasserian  ganglion,  162 

—  in  facial  paralysis,  165 
Lingual  nerve,  163 
Lumbar  plexus,  287 

—  roots,  distribution  of,  283 

Massage  in  nerve  injuries,  73,  78, 

143 
Median  nerve,  262 

fuU  supply  of,  267 

injury,  diagnosis  of,  270 

motor  symptoms,  267 

sensory   symptoms,  264 

—  and  ulnar  nerves,  271 


308 


INDEX 


Meralgia  parsesthetica,  289 
Motility,  supplementary,  28 
Musculo-ciitarLeous  nerve,  230 
Musculo- spiral  nerve,  232 

injiuy  in  fractures,  234 

treatment,  242 

Nails,  clianges  in,  32,  44 
Neiu-itis,  118,  132,  140,  142 

—  of  ulnar  nerve,  258 
Neuromata,  amputation,  147 
Neurolysis,  131,  146,  245 

Obturator  nerve,  288 
Operations,  nerve  injuries  caused 
by,  4,  144,  167,  175 

—  plastic,  on  nerves,  85 

Pain  in  nerve  injuries,  43,  132 

—  following  amputations,  148 

—  treatment  of,  139,  142,  145 
Palate,  motor  supply  of,  160,  166, 

174 
Paralysis,  brachial  birth,  206 

—  diaphragm,  179 

—  Erb-Duchenne^  195,  288 

—  following  complete  division,  27 
crutch  pressure,  6 

incomplete  division,  40 

splint  pressure,  6 

—  Klumpke,  199 

—  palate  of,  160 

—  post-ansesthetic,  10,  189 

—  post-operative,  10 

—  serratus  magnus,  of,  160 

—  sterno-mastoid,  175 

—  trapezius  of,  175 
Phrenic  nerve,  179 
Primary  suture,  75 


Primary  suture,recovery  af  ter,108 
prognosis  of,  110 

—  rmion,  99 

Prognosis  of  brachial  birth  para- 
lysis, 208 

—  of  incomplete  division,  131 

—  of  brachial  plexus  injuries,  190, 

204 

—  of  post-ansesthetic  paralyses, 

12 

—  of  primary  suture,  110 

—  of  secondary  suture,  114 

See  also  under  Individual  nerve. 
Protopathic  sensibility,  20 

recovery  of,  101 

tests  for,  53 

Pupil,  changes  in,  following  injury 
to  cervical  sympathetic,  181 

—  removal  of  Gasserian  ganglion, 

162 

—  spinal  cord  injury,  224 

Radial  nerve,  233,  239 

—  and  external  cutaneous,  240 
Reactions,  electrical,  in  complete 

division,  28 

—  in  incomplete  division,  48 

—  in  testing,  55 
Recurrent  laryngeal  nerve,  174 

—  sensibility,  22 

Recovery,      after      anastomosis, 

facial,  171 
for  injury,  93 

—  after  complete  division,  101 

—  after  incomplete  division,  123 

—  after  primary  suture,  108 

—  after  secondary  suture,  112 

—  after  transplantation,  89 

—  after  tubular  suture,  90 
Regeneration,  119 


INDEX 


309 


Ehomboid  muscles,  paralysis  of, 

215,  255 
Eoots,  nerve,  division  of,  143,  149 

—  loss  of  sensibility  following,  24 

—  supply  of  cervical,  184,  186 
of  sacral,  286 

Sacral  plexus,  287 

—  roots,  282 

Scapula,  alterations  in  position, 
219 

—  winged,  212 

Scars,  nerve  involvement  in,  132, 

139 
Sciatic  nerve,  great,  291 

—  —  plastic  operations  on,  97 

small,  297 

Sensibility,  deep,  17 

—  dissociated,  23,  25 

—  epicritic,  20 

—  protopathic,  28 

—  rapid   retiirn  of,  after  secon- 

dary sutiu-e,  113 

—  recoveiy  of,  101 

—  supplementary,  23 

—  tests  foi',  48 

Serratus    magnus,   paralysis    of, 

211,  225 
Sixth  cranial  nerve,  154 
Skin,  changes  following  complete 

division,  30 

—  —  —  incomplete  division,  42 

—  grafting,   recovery   of   sensa- 

tion after,  106 
Spinal  accessory  nerve,  175 

—  cord  injuries,  diagnosis  of,  61, 

222 
Spinati  muscles,  paralysis  of,  214, 
225 


Stretching,    nerve  in   secondary 

suture,  82 
Supra-scapular  nerve,  214,  266 
Supply,  exclusive,  15 

—  full,  15 

Suture,  primary,  75,  108 

—  secondary,  79,  112 

—  tubular,  90,  97 
Sweating,  absence  of,  30,  181 

—  increase  of,  44,  139,  182 

Taste,  158 

—  nerves  of,  165 

—  tests  for,  159 
Tests,  compass,  51 

—  electrical,  55 

—  for  deep  touch,  54 

—  for  light  touch,  48 

—  for  passive  position,  54 

—  for  pain,  53 

—  for  smell,  151 

—  for  taste,  159 

—  sensory,  48 

—  temperattu-e,  49,  53 
Third  cranial  nerve,  153 
Transplantation,  definition  of,  85, 

86 

—  prognosis  of,  89 

—  varieties  of,  87 
Trapezius,  paralysis  of,  175 
Treatment,  72 

—  of  amputation  neiu'omata,  149 

—  of  brachial    plexus    injru-ies, 

202 

—  of  brachial  birth  paralysis,  209 

—  of  facial  paralysis,  167 

—  of  gimshot  wounds,  84 

—  of  subcutaneous  injm-ies,  73 
involvement  in  f  ractia-es. 


!10 


INDEX 


Treatment  of  scars,  134,  139 
—  T^oimds,  74 

Ulcers,  "tropMc,"  31,  44,  81,  118 
Ulnar  nerve,  246 

diagnosis  of  injuries,  261 

dislocation,  260 

fvill  supply,  253 

injiu^ies  in  fractures,  256 

prognosis  of  injuries,  254 

treatment,  254 


Yagns  nerve,  173 
Volkman's  contracture,  70 


Wounds  of  nerves,  accidental,  3, 
74 

gunshot,  12,  42,  84 

operative,  4,  74 


Zone,  intermediate,  17,  18 


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